Home » If sin (theta) = cos (theta), find (theta) between 0o and 360o

If sin (theta) = cos (theta), find (theta) between 0o and 360o

If sin (theta) = cos (theta), find (theta) between 0o and 360o

  • A.
    45o, 225o
  • B.
    135o, 315o
  • C.
    45o, 315o
  • D.
    135o, 225o
Correct Answer: Option A
Explanation

sin (theta) = cos (theta) 0 (leq) (theta) (leq) 360o
The acute angle where sin (theta) = cos (theta) = 45o
But at the third Quadrant Cos (theta) = -ve; sin (theta) = -ve.
at the 3rd quadrant, value with respect to Q is
(180 + Q) where Q = acute angle
(180 + 45) = 225°
The two solution are 45°, 225°