If Cos \(\theta\) = \(\frac{12}{13}\). Find 1 + cot\(^2\)\(\theta\)
A
\(\frac{169}{25}\)
B
\(\frac{25}{169}\)
C
\(\frac{169}{144}\)
D
\(\frac{144}{169}\)
Verified Correct Answer: A.
Step-by-Step Mathematical Solution
Cos \(\theta\) = \(\frac{12}{13}\)
x\(^2\) + 12\(^2\) = 13\(^2\)
x\(^2\) = 169- 144 = 25
x = \(\sqrt{25}\) = 5
Hence, tan\(\theta\) = \(\frac{5}{12}\) and cos\(\theta\) = \(\frac{12}{13}\)
If cot\(^2\)\(\theta\) = 1 + \(\frac{1}{tan^2\theta}\)
= 1 + \(\frac{1}{\frac{(5)^2}{12^2}}\)
= 1 + \(\frac{1}{\frac{25}{144}}\)
= 1 + \(\frac{144}{25}\)
= \(\frac{25 + 144}{25}\)
= \(\frac{169}{25}\)
Source: Myschool Past Questions Archive (Record #31478)