### Home > CALC > Chapter 4 > Lesson 4.5.1 > Problem 4-165

4-165.

Solve for

*x*. Assume*x*is measured in radians. Hint: First use a substitution to make the problem easier. Homework Help ✎2sin

^{2}(*x*+ 1) − sin(*x*+ 1) − 1 = 0

Let *U* = sin(*x* + 1)

so 2*U*^{2} − *U* − 1 = 0

Solve for U, then substitute to solve for x.

Remember to mention ALL solutions.

Let *U* = *x*^{2} − 2*x* + 1