Given that cos x = (frac{12}{13}), evaluate (frac{1 – tan x}{tan x})
-
A.
(frac{5}{13}) -
B.
(frac{5}{7}) -
C.
(frac{7}{5}) -
D.
(frac{13}{5})
Correct Answer: Option C
Explanation
cos x(frac{12}{13})
132 = 122 + a2
169 = 144 + a2
a2 = 169 – 144
a2 = 25
a (sqrt{25})
a = 5
tan x = (frac{5}{12})
(frac{1 – tan x}{tan x} = frac{1 – frac{5}{12}}{frac{5}{12}})
(frac{frac{1 – frac{5}{12}}{12 – 5}}{12} = frac{frac{7}{12}}{frac{5}{12}})
= (frac{7}{2} div frac{5}{12})
= (frac{7}{12} times frac{12}{5} = frac{7}{5})