Solve for x in degrees: sinx=cos (48) without a calculator

We are given with the mathematical expression sinx=cos (48) and is asked in the porblem to determine the value of variable x. In this case, we solve first cos 48 which is equal to - 0.64. to determine x, we use inverse sin, that is sin-1 (-0.64) = x; x = 42 degrees. x is equal also to 90-48 according to complementary postulate.