Without using tables, find the value of (frac{sin 20°}{cos 70°} + frac{cos 25°}{sin 65°})
-
A.
2 -
B.
1 -
C.
o -
D.
-1 -
E.
-2
Correct Answer: Option A
Explanation
Note: sin 20° = cos 70° hence
(frac{sin 20}{cos 70} = 1)
Also, cos 65° = sin 25°
(frac{cos 65}{sin 25} = 1)
(therefore frac{sin 20}{cos 70} + frac{cos 65}{sin 25})
= 1 + 1
= 2