Evaluate the following Integrals:

Given Definite Integral can be written as:
……(1)
We know that: 
And 
Let us find the value of 5cosx+3sinx


We know that: 1+tan2x = sec2x
……(2)
Substituting (2) in (1) we get,

Let us assume: ![]()
Differentiating on both sides w.r.t x we get,
![]()
……(3)
The upper limit for the Definite Integral:
![]()
⇒ t=1……(4)
The lower limit for the Definite Integral:
![]()
⇒ t=0……(5)
Substituting (3),(4),(5) in the eq(1) we get,


We need to convert the denominator into standard forms



We know that: ![]()
In this problem the values, ![]()
Using these values and the standard result, we get,




We know that: ![]()
[here f’(x) is derivative of f(x))


We know that: ![]()





