Below is a list of integrals ( primitive functions) of irrational functions . In the list, the additive integration constant is omitted everywhere.
Integrals with a root of a 2 + x 2
Everywhere below: {\ displaystyle r = {\ sqrt {a ^ {2} + x ^ {2}}}} .
- {\ displaystyle \ int r \; dx = {\ frac {1} {2}} \ left (xr + a ^ {2} \, \ ln \ left ({x + r} \ right) \ right)}
- {\ displaystyle \ int r ^ {3} \; dx = {\ frac {1} {4}} xr ^ {3} + {\ frac {1} {8}} 3a ^ {2} xr + {\ frac { 3} {8}} a ^ {4} \ ln \ left ({\ frac {x + r} {a}} \ right)}
- {\ displaystyle \ int r ^ {5} \; dx = {\ frac {1} {6}} xr ^ {5} + {\ frac {5} {24}} a ^ {2} xr ^ {3} + {\ frac {5} {16}} a ^ {4} xr + {\ frac {5} {16}} a ^ {6} \ ln \ left ({\ frac {x + r} {a}} \ right)}
- {\ displaystyle \ int xr ^ {2n + 1} \; dx = {\ frac {r ^ {2n + 3}} {2n + 3}}}
- {\ displaystyle \ int x ^ {2} r \; dx = {\ frac {xr ^ {3}} {4}} - {\ frac {a ^ {2} xr} {8}} - {\ frac { a ^ {4}} {8}} \ ln \ left ({\ frac {x + r} {a}} \ right)}
- {\ displaystyle \ int x ^ {2} r ^ {3} \; dx = {\ frac {xr ^ {5}} {6}} - {\ frac {a ^ {2} xr ^ {3}} { 24}} - {\ frac {a ^ {4} xr} {16}} - {\ frac {a ^ {6}} {16}} \ ln \ left ({\ frac {x + r} {a} } \ right)}
- {\ displaystyle \ int x ^ {3} r \; dx = {\ frac {r ^ {5}} {5}} - {\ frac {a ^ {2} r ^ {3}} {3}}}
- {\ displaystyle \ int x ^ {3} r ^ {3} \; dx = {\ frac {r ^ {7}} {7}} - {\ frac {a ^ {2} r ^ {5}} { five}}}
- {\ displaystyle \ int x ^ {3} r ^ {2n + 1} \; dx = {\ frac {r ^ {2n + 5}} {2n + 5}} - {\ frac {a ^ {3} r ^ {2n + 3}} {2n + 3}}}
- {\ displaystyle \ int x ^ {4} r \; dx = {\ frac {x ^ {3} r ^ {3}} {6}} - {\ frac {a ^ {2} xr ^ {3}} {8}} + {\ frac {a ^ {4} xr} {16}} + {\ frac {a ^ {6}} {16}} \ ln \ left ({\ frac {x + r} {a }} \ right)}
- {\ displaystyle \ int x ^ {4} r ^ {3} \; dx = {\ frac {x ^ {3} r ^ {5}} {8}} - {\ frac {a ^ {2} xr ^ {5}} {16}} + {\ frac {a ^ {4} xr ^ {3}} {64}} + {\ frac {3a ^ {6} xr} {128}} + {\ frac {3a ^ {8}} {128}} \ ln \ left ({\ frac {x + r} {a}} \ right)}
- {\ displaystyle \ int x ^ {5} r \; dx = {\ frac {r ^ {7}} {7}} - {\ frac {2a ^ {2} r ^ {5}} {5}} + {\ frac {a ^ {4} r ^ {3}} {3}}}
- {\ displaystyle \ int x ^ {5} r ^ {3} \; dx = {\ frac {r ^ {9}} {9}} - {\ frac {2a ^ {2} r ^ {7}} { 7}} + {\ frac {a ^ {4} r ^ {5}} {5}}}
- {\ displaystyle \ int x ^ {5} r ^ {2n + 1} \; dx = {\ frac {r ^ {2n + 7}} {2n + 7}} - {\ frac {2a ^ {2} r ^ {2n + 5}} {2n + 5}} + {\ frac {a ^ {4} r ^ {2n + 3}} {2n + 3}}}
- {\ displaystyle \ int {\ frac {r \; dx} {x}} = ra \ ln \ left | {\ frac {a + r} {x}} \ right | = ra \ operatorname {arsh} {\ frac {a} {x}}}
- {\ displaystyle \ int {\ frac {r ^ {3} \; dx} {x}} = {\ frac {r ^ {3}} {3}} + a ^ {2} ra ^ {3} \ ln \ left | {\ frac {a + r} {x}} \ right |}
- {\ displaystyle \ int {\ frac {r ^ {5} \; dx} {x}} = {\ frac {r ^ {5}} {5}} + {\ frac {a ^ {2} r ^ { 3}} {3}} + a ^ {4} ra ^ {5} \ ln \ left | {\ frac {a + r} {x}} \ right |}
- {\ displaystyle \ int {\ frac {r ^ {7} \; dx} {x}} = {\ frac {r ^ {7}} {7}} + {\ frac {a ^ {2} r ^ { 5}} {5}} + {\ frac {a ^ {4} r ^ {3}} {3}} + a ^ {6} ra ^ {7} \ ln \ left | {\ frac {a + r } {x}} \ right |}
- {\ displaystyle \ int {\ frac {dx} {r}} = \ operatorname {arsh} {\ frac {x} {a}} = \ ln \ left | x + r \ right |}
- {\ displaystyle \ int {\ frac {x \, dx} {r}} = r}
- {\ displaystyle \ int {\ frac {x ^ {2} \; dx} {r}} = {\ frac {x} {2}} r - {\ frac {a ^ {2}} {2}} \ , \ operatorname {arsh} {\ frac {x} {a}} = {\ frac {x} {2}} r - {\ frac {a ^ {2}} {2}} \ ln \ left | x + r \ right |}
- {\ displaystyle \ int {\ frac {dx} {xr}} = - {\ frac {1} {a}} \, \ operatorname {arsh} {\ frac {a} {x}} = - {\ frac { 1} {a}} \ ln \ left | {\ frac {a + r} {x}} \ right |}
Integrals with root of x 2 - a 2
Everywhere below: {\ displaystyle s = {\ sqrt {x ^ {2} -a ^ {2}}}} .
Accepted {\ displaystyle x ^ {2}> a ^ {2}} for {\ displaystyle x ^ {2} <a ^ {2}} see the next section.
- {\ displaystyle \ int s \; dx = {\ frac {1} {2}} \ left (xs-a ^ {2} \ ln \ left (x + s \ right) \ right)}
- {\ displaystyle \ int xs \; dx = {\ frac {1} {3}} s ^ {3}}
- {\ displaystyle \ int {\ frac {s \; dx} {x}} = sa \ cos ^ {- 1} \ left | {\ frac {a} {x}} \ right |}
- {\ displaystyle \ int {\ frac {dx} {s}} = \ int {\ frac {dx} {\ sqrt {x ^ {2} -a ^ {2}}}} = \ ln \ left | x + s \ right |}
notice, that {\ displaystyle \ ln \ left | {\ frac {x + s} {a}} \ right | = \ mathrm {sgn} (x) \ operatorname {arch} \ left | {\ frac {x} {a}} \ right | = {\ frac {1} {2}} \ ln \ left ({\ frac {x + s} {xs}} \ right)} where {\ displaystyle \ operatorname {arch} \ left | {\ frac {x} {a}} \ right |} accepts only positive values.
- {\ displaystyle \ int {\ frac {x \; dx} {s}} = s}
- {\ displaystyle \ int {\ frac {x \; dx} {s ^ {3}}} = - {\ frac {1} {s}}}
- {\ displaystyle \ int {\ frac {x \; dx} {s ^ {5}}} = - {\ frac {1} {3s ^ {3}}}}
- {\ displaystyle \ int {\ frac {x \; dx} {s ^ {7}}} = - {\ frac {1} {5s ^ {5}}}}
- {\ displaystyle \ int {\ frac {x \; dx} {s ^ {2n + 1}}} = - {\ frac {1} {(2n-1) s ^ {2n-1}}}}
- {\ displaystyle \ int {\ frac {x ^ {2m} \; dx} {s ^ {2n + 1}}} = - {\ frac {1} {2n-1}} {\ frac {x ^ {2m -1}} {s ^ {2n-1}}} + {\ frac {2m-1} {2n-1}} \ int {\ frac {x ^ {2m-2} \; dx} {s ^ { 2n-1}}}}
- {\ displaystyle \ int {\ frac {x ^ {2} \; dx} {s}} = {\ frac {xs} {2}} + {\ frac {a ^ {2}} {2}} \ ln \ left | {\ frac {x + s} {a}} \ right |}
- {\ displaystyle \ int {\ frac {x ^ {2} \; dx} {s ^ {3}}} = - {\ frac {x} {s}} + \ ln \ left | {\ frac {x + s} {a}} \ right |}
- {\ displaystyle \ int {\ frac {x ^ {4} \; dx} {s}} = {\ frac {x ^ {3} s} {4}} + {\ frac {3} {8}} a ^ {2} xs + {\ frac {3} {8}} a ^ {4} \ ln \ left | {\ frac {x + s} {a}} \ right |}
- {\ displaystyle \ int {\ frac {x ^ {4} \; dx} {s ^ {3}}} = {\ frac {xs} {2}} - {\ frac {a ^ {2} x} { s}} + {\ frac {3} {2}} a ^ {2} \ ln \ left | {\ frac {x + s} {a}} \ right |}
- {\ displaystyle \ int {\ frac {x ^ {4} \; dx} {s ^ {5}}} = - {\ frac {x} {s}} - {\ frac {1} {3}} { \ frac {x ^ {3}} {s ^ {3}}} + \ ln \ left | {\ frac {x + s} {a}} \ right |}
- {\ displaystyle \ int {\ frac {x ^ {2m} \; dx} {s ^ {2n + 1}}} = (- 1) ^ {nm} {\ frac {1} {a ^ {2 (nm )}}} \ sum _ {i = 0} ^ {nm-1} {\ frac {1} {2 (m + i) +1}} {nm-1 \ choose i} {\ frac {x ^ { 2 (m + i) +1}} {s ^ {2 (m + i) +1}}},} Where {\ displaystyle n> m \ geq 0}
- {\ displaystyle \ int {\ frac {dx} {s ^ {3}}} = - {\ frac {1} {a ^ {2}}} {\ frac {x} {s}}}
- {\ displaystyle \ int {\ frac {dx} {s ^ {5}}} = {\ frac {1} {a ^ {4}}} \ left [{\ frac {x} {s}} - {\ frac {1} {3}} {\ frac {x ^ {3}} {s ^ {3}}} \ right]}
- {\ displaystyle \ int {\ frac {dx} {s ^ {7}}} = - {\ frac {1} {a ^ {6}}} \ left [{\ frac {x} {s}} - { \ frac {2} {3}} {\ frac {x ^ {3}} {s ^ {3}}} + {\ frac {1} {5}} {\ frac {x ^ {5}} {s ^ {5}}} \ right]}
- {\ displaystyle \ int {\ frac {dx} {s ^ {9}}} = {\ frac {1} {a ^ {8}}} \ left [{\ frac {x} {s}} - {\ frac {3} {3}} {\ frac {x ^ {3}} {s ^ {3}}} + {\ frac {3} {5}} {\ frac {x ^ {5}} {s ^ {5}}} - {\ frac {1} {7}} {\ frac {x ^ {7}} {s ^ {7}}} \ right]}
- {\ displaystyle \ int {\ frac {x ^ {2} \; dx} {s ^ {5}}} = - {\ frac {1} {a ^ {2}}} {\ frac {x ^ {3 }} {3s ^ {3}}}}
- {\ displaystyle \ int {\ frac {x ^ {2} \; dx} {s ^ {7}}} = {\ frac {1} {a ^ {4}}} \ left [{\ frac {1} {3}} {\ frac {x ^ {3}} {s ^ {3}}} - {\ frac {1} {5}} {\ frac {x ^ {5}} {s ^ {5}} } \ right]}
- {\ displaystyle \ int {\ frac {x ^ {2} \; dx} {s ^ {9}}} = - {\ frac {1} {a ^ {6}}} \ left [{\ frac {1 } {3}} {\ frac {x ^ {3}} {s ^ {3}}} - {\ frac {2} {5}} {\ frac {x ^ {5}} {s ^ {5} }} + {\ frac {1} {7}} {\ frac {x ^ {7}} {s ^ {7}}} \ right]}
Integrals with a root of a 2 - x 2
Everywhere below: {\ displaystyle t = {\ sqrt {a ^ {2} -x ^ {2}}} \ qquad {\ mbox {(}} | x | \ leqslant | a | {\ mbox {)}}}
- {\ displaystyle \ int t \; dx = {\ frac {1} {2}} \ left (xt + a ^ {2} \ arcsin {\ frac {x} {a}} \ right) = {\ frac { 1} {2}} \ left (xt-a ^ {2} \ arccos {\ frac {x} {a}} \ right)}
- {\ displaystyle \ int xt \; dx = - {\ frac {1} {3}} t ^ {3}}
- {\ displaystyle \ int {\ frac {t \; dx} {x}} = ta \ ln \ left | {\ frac {a + t} {x}} \ right |}
- {\ displaystyle \ int {\ frac {dx} {t}} = \ arcsin {\ frac {x} {a}}}
- {\ displaystyle \ int {\ frac {x \; dx} {t}} = - t}
- {\ displaystyle \ int {\ frac {x ^ {2} \; dx} {t}} = - {\ frac {x} {2}} t + {\ frac {a ^ {2}} {2}} \ arcsin {\ frac {x} {a}}}
- {\ displaystyle \ int t \; dx = {\ frac {1} {2}} \ left (xt- \ operatorname {sgn} x \, \ operatorname {arch} \ left | {\ frac {x} {a} } \ right | \ right)}
Integrals with a root from a common square trinomial
It is indicated here: {\ displaystyle R = ax ^ {2} + bx + c}
- {\ displaystyle \ int {\ frac {dx} {\ sqrt {ax ^ {2} + bx + c}}} = {\ frac {1} {\ sqrt {a}}} \ ln \ left | 2 {\ sqrt {aR}} + 2ax + b \ right | \ qquad {\ mbox {(}} a> 0 {\ mbox {)}}}
- {\ displaystyle \ int {\ frac {dx} {\ sqrt {ax ^ {2} + bx + c}}} = {\ frac {1} {\ sqrt {a}}} \, \ operatorname {arsh} { \ frac {2ax + b} {\ sqrt {4ac-b ^ {2}}}} \ qquad {\ mbox {(}} a> 0 {\ mbox {,}} 4ac-b ^ {2}> 0 { \ mbox {)}}}
- {\ displaystyle \ int {\ frac {dx} {\ sqrt {ax ^ {2} + bx + c}}} = {\ frac {1} {\ sqrt {a}}} \ ln | 2ax + b | \ quad {\ mbox {(}} a> 0 {\ mbox {,}} 4ac-b ^ {2} = 0 {\ mbox {)}}}
- {\ displaystyle \ int {\ frac {dx} {\ sqrt {ax ^ {2} + bx + c}}} = - {\ frac {1} {\ sqrt {-a}}} \ arcsin {\ frac { 2ax + b} {\ sqrt {b ^ {2} -4ac}}} \ qquad {\ mbox {(}} a <0 {\ mbox {,}} 4ac-b ^ {2} <0 {\ mbox { )}}}
- {\ displaystyle \ int {\ frac {dx} {\ sqrt {(ax ^ {2} + bx + c) ^ {3}}}} = {\ frac {4ax + 2b} {(4ac-b ^ {2 }) {\ sqrt {R}}}}}
- {\ displaystyle \ int {\ frac {dx} {\ sqrt {(ax ^ {2} + bx + c) ^ {5}}}} = {\ frac {4ax + 2b} {3 (4ac-b ^ { 2}) {\ sqrt {R}}}} \ left ({\ frac {1} {R}} + {\ frac {8a} {4ac-b ^ {2}}} \ right)}
- {\ displaystyle \ int {\ frac {dx} {\ sqrt {(ax ^ {2} + bx + c) ^ {2n + 1}}}} = {\ frac {4ax + 2b} {(2n-1) (4ac-b ^ {2}) R ^ {(2n-1) / 2}}} + {\ frac {8a (n-1)} {(2n-1) (4ac-b ^ {2})} } \ int {\ frac {dx} {R ^ {(2n-1) / 2}}}}
- {\ displaystyle \ int {\ frac {x \; dx} {\ sqrt {ax ^ {2} + bx + c}}} = {\ frac {\ sqrt {R}} {a}} - {\ frac { b} {2a}} \ int {\ frac {dx} {\ sqrt {R}}}}
- {\ displaystyle \ int {\ frac {x \; dx} {\ sqrt {(ax ^ {2} + bx + c) ^ {3}}}} = - {\ frac {2bx + 4c} {(4ac- b ^ {2}) {\ sqrt {R}}}}}
- {\ displaystyle \ int {\ frac {x \; dx} {\ sqrt {(ax ^ {2} + bx + c) ^ {2n + 1}}}} = - {\ frac {1} {(2n- 1) aR ^ {(2n-1) / 2}}} - {\ frac {b} {2a}} \ int {\ frac {dx} {R ^ {(2n + 1) / 2}}}}
- {\ displaystyle \ int {\ frac {dx} {x {\ sqrt {ax ^ {2} + bx + c}}}} = - {\ frac {1} {\ sqrt {c}}} \ ln \ left ({\ frac {2 {\ sqrt {cR}} + bx + 2c} {x}} \ right)}
- {\ displaystyle \ int {\ frac {dx} {x {\ sqrt {ax ^ {2} + bx + c}}}} = - {\ frac {1} {\ sqrt {c}}} \ operatorname {arsh } \ left ({\ frac {bx + 2c} {| x | {\ sqrt {4ac-b ^ {2}}}}} \ right)}
Integrals with a root from a linear function
- {\ displaystyle \ int {\ frac {dx} {x {\ sqrt {ax + b}}}}, = \, {\ frac {-2} {\ sqrt {b}}} \ operatorname {arth} { \ sqrt {\ frac {ax + b} {b}}}}
- {\ displaystyle \ int {\ frac {\ sqrt {ax + b}} {x}} \, dx \; = \; 2 \ left ({\ sqrt {ax + b}} - {\ sqrt {b}} \ operatorname {arth} {\ sqrt {\ frac {ax + b} {b}}} \ right)}
- {\ displaystyle \ int {\ frac {x ^ {n}} {\ sqrt {ax + b}}} \, dx \; = \; {\ frac {2} {a (2n + 1)}} left (x ^ {n} {\ sqrt {ax + b}} - bn \ int {\ frac {x ^ {n-1}} {\ sqrt {ax + b}}}, dx \ right)}
- {\ displaystyle \ int x ^ {n} {\ sqrt {ax + b}} \, dx \; = \; {\ frac {2} {2n + 1}} \ left (x ^ {n + 1} { \ sqrt {ax + b}} + bx ^ {n} {\ sqrt {ax + b}} - nb \ int x ^ {n-1} {\ sqrt {ax + b}} \, dx \ right)}
Bibliography
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- D. Zwillinger. CRC Standard Mathematical Tables and Formulae , 31st ed., 2002. ISBN 1-58488-291-3 .
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- Korn G.A., Korn T.M. Math reference book for scientists and engineers . - M .: " Science ", 1974.
- Integral Tables
- Calculation of Integrals
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- Empire of Numbers