WAEC - Mathematics (2016 - No. 19)
If cos \(\theta\) = x and sin 60o = x + 0.5 0o < \(\theta\) < 90o, find, correct to the nearest degree, the value of \(\theta\)
32o
40o
60o
69o
Explanation
sin 60o = x + 0.5 0o(given)
0.8660 = x + 0.5
0.8660 - 0.5 = x
x = 0.3660
cos\(\theta\) = x(given)
cos\(\theta\) = 0.3660
Hence, \(\theta\) = cos-1(0.3660)
= 68.53o
= 69o (nearest degree)
0.8660 = x + 0.5
0.8660 - 0.5 = x
x = 0.3660
cos\(\theta\) = x(given)
cos\(\theta\) = 0.3660
Hence, \(\theta\) = cos-1(0.3660)
= 68.53o
= 69o (nearest degree)
Comments (0)
