If sec2θ + tan2θ = 3, then the angle θ is equal to?
Answer Details
We're given the equation sec²θ + tan²θ = 3, and we need to solve for θ.
One way to approach this is to use the trigonometric identity:
tan²θ + 1 = sec²θ
Substituting this into the given equation, we get:
tan²θ + 1 + tan²θ = 3
Simplifying this equation, we get:
2tan²θ = 2
Dividing both sides by 2, we get:
tan²θ = 1
Taking the square root of both sides, we get:
tanθ = ±1
This means that θ must be one of the angles whose tangent is ±1. These angles are 45º and 225º (or -135º), since tangent is positive in the first and third quadrants, and negative in the second and fourth quadrants.
However, we need to check whether these values of θ satisfy the original equation. Let's start with θ = 45º:
sec²45º + tan²45º = 2 + 1 = 3
So this value of θ does satisfy the equation, and therefore it is the solution.
Therefore, the angle θ is 45º.
So the answer is (c) 45º.