Act Math Practice
Trigonometry Answer 4
© 2008 ACT-Math-Practice.com
Trigonometry Answer 4:
4. Angles
Ð
A and
Ð
B each have measurements between 0° and 45°. If cos A = sin B, what is the sum of
Ð
A +
Ð
B ?
F. 15
G. 30
H. 45
J. 90
K. 180
The correct answer is J.
Remember these important trigonometric formulas:
cos A = sin (90°- A)
sin A = cos (90°- A)
If sin B = cos A, as in this problem, then B = 90° - A
So A + B = A + (90° - A)
A + B = A + 90° - A
A + B = A - A + 90
A + B = 90°
Leave Trigonometry Answer 4 and Return to the ACT Math Scores Page
