Math, asked by rj319805, 10 months ago

integration cos4x cos5x sin2x dx

Attachments:

Answers

Answered by amitnrw
5

Given : ∫cos4x cos5x sin2xdx

To Find : Integrate

Solution:

I =   ∫cos4x cos5x sin2xdx

Simplify cos4x cos5x sin2x

= 2cos5x cos4x sin2x /2

2Cosacosb = Cos(a - b) + Cos(a + b)

= ( Cosx + cos 9x)sin2x/2

= Cosxsin2x/2  + cos9xsin2x/2

sin2x = 2sinx.cosx

= Cosxsinx.cosx  + cos9xsin2x/2

= cos²xsinx  + 2sin2xcos9x/4

2sinacosb  = sin(a + b) + sin(a - b)

= cos²xsinx  + {Sin11x  + sin(-7x)}/4

= cos²xsinx  + {Sin11x  -  sin(7x)}/4

= cos²xsinx  + Sin11x/4  - Sin7x/4

I = ∫ cos²xsinx  + Sin11x/4  - Sin7x/4) dx

=  ∫(cos²xsinxdx  +(1/4) ∫Sin11x .dx  - (1/4) ∫Sin7x dx

∫(cos²xsinxdx  

cosx = y ,  -sinxdx = dy  

=> -∫y²dy   =  - y³/3  + c   =      -cos³x /3  + c

(1/4) ∫Sin11x .dx  - (1/4) ∫Sin7x dx

= (1/4) -Cos11x/11  -(1/4)(-cos7x)/7  + c

I =   -cos³x /3  - cos11x /44  + Cos7x/2x + C

Learn More:

integral of 6x-5 root of 6-2x^2+xdx evaluate - Brainly.in

https://brainly.in/question/15708198

integrate x³-1/x³+x dx - Brainly.in

https://brainly.in/question/3017912

Integrate dx/ 3sin^2x+5cos^2x - Brainly.in

https://brainly.in/question/9262036

Similar questions