Question 641824
sin(x) = cos(90-x), therefore
sin(30) = cos(90-30) = cos(60) = 1/2
Your expression
(1) sin^2(30) + cos^2(60) simplifies to
(2) sin^2(30) + sin^2(30) or
(3) 2*sin^2(30)
Numerically (3) becomes
(4) 2*(1/2)^2 = 1/2
The exact value of (1) is 1/2