Answer:
Option A is correct.
Solution for the given equation is,
Step-by-step explanation:
Given that : Let then our equation become; .....[1]
A quadratic equation is of the form:
.....[2] where a, b and c are coefficient and the solution is given by;
Comparing equation [1] and [2] we get;
a = 2 b = -1 and c =-1
then;Simplify:or and
Simplify:y = 1 and
Substitute y = cos x we have;⇒and⇒
The solution set:
Therefore, the solution for the given equation is, 0 degrees
