If tan theta=3/4 then find the value ofcos^2 theta - sin ^2 theta
tanØ = 3/4 = y/x
so x=4 and y=3 OR x = -4, y = -3
r^2 = x^2 + y^2
= 25
r = 5
cos^2 Ø - sin^2 Ø
= (4/5)^2 - (3/5)^2
= 16/25 - 9/25
= 7/25
so x=4 and y=3 OR x = -4, y = -3
r^2 = x^2 + y^2
= 25
r = 5
cos^2 Ø - sin^2 Ø
= (4/5)^2 - (3/5)^2
= 16/25 - 9/25
= 7/25