Solution: We have 4tanA = 3 so, tanA = 3/4
Now, (4sinA - cosA)/(4sinA + cosA)
First of all divide by cosA on both LHS and RHS ,
(4sinA/cosA - cosA/cosA)/(4sinA/cosA + cosA/cosA)
= (4tanA - 1)/(4tanA + 1)
Now, put tanA = 3/4
= (4 × 3/4 - 1)/(4 × 3/4 + 1)
= (3 - 1)/(3 + 1)
= 2/4 = 1/2