What is the value, in radians, of the largest angle $x$ in the range $0 \leq x \leq 2 \pi$ that satisfies the equation $8 \sin ^ { 2 } x + 4 \cos ^ { 2 } x = 7$ ?
& C & 3 & D
What is the value, in radians, of the largest angle $x$ in the range $0 \leq x \leq 2 \pi$ that satisfies the equation $8 \sin ^ { 2 } x + 4 \cos ^ { 2 } x = 7$ ?