Mathematics

Without using tables, find the value of (frac{sin 20°}{cos 70°} + frac{cos 25°}{sin 65°})

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