Edited : I apologise I misunderstood the question.
You can solve the equation.
I think what you meant was
(2x - 5)² = 11 -- (1)
Square root both sides of (1), i.e.
√(2x - 5)² = ± √11 -- (2)
From (2), we have
2x - 5 = ± √11 -- (3)
By adding 5 to both sides in (3), we have
2x = 5 ± √11 -- (4)
Divide both sides of (4) by 2, and we obtain
x = (5 ± √11)/2 -- (5)
From (5), the solution set of (1) is
x = (5 + √11)/2, (5 - √11)/2 ...Ans.
Since the sine and cosine functions are cofunctions, they are complementary. The format for this is that sinx=cos(90-x). This works for secant and cosecant and tangent and cotangent. So, sin25°=cos65°.
