### Home > INT3 > Chapter Ch11 > Lesson 11.2.2 > Problem 11-72

11-72.

The sine of obtuse angle *A* is *A*? Homework Help ✎

First use sin^{2}*A* + cos^{2}*A* = 1 to find cos*A*.

Note that *A* is in the second quadrant.

11-72.

The sine of obtuse angle *A* is *A*? Homework Help ✎

First use sin^{2}*A* + cos^{2}*A* = 1 to find cos*A*.

Note that *A* is in the second quadrant.