Select one or more expressions that together represent all solutions to the equation. Your answer should be in degrees.
Assume n is any integer.
7cos(5x)+9=12
Choose all answers that apply:
Choose all answers that apply:
A −115.38∘+n⋅360∘
B −16.48∘+n⋅180∘
C −12.92∘+n⋅72∘
D 12.92∘+n⋅72∘
E 16.48∘+n⋅180∘
F 115.38∘+n⋅360∘
+130081 7cos(5x) + 9 =12 subtract 9 from both sides
7cos(5x) = 3 divide both sides by 7
cos(5x) = 3/7
Let q = 5x
So ....cos ( q ) = 3/7 at q ≈ 64.623° + n360° and at q = -64.623° + n360°
So
q = 5x = 64.623° + n360°
Divide by 5
x = 12.92° + n72°
And
q = 5x = 64.623° + n360°
Divide by 5
x = -12.92° + n72°
