Question

Which of the following is not a fundamental​ identity?

A.
`1 = sin^2\theta + cos^2\theta`
B.
`cos\theta= (tan\theta)/(sin\theta)`
C.
`1+tan^2\theta = sec^2\theta`
D.
`cot\theta = (1)/(tan\theta)`

Answer 1

Answer:b

Explanation:

Given

Option a is correct because it is Pythagorean identity

`1=\sin^2\theta +\cos^2\theta`

Option b is incorrect because

`\tan \theta =(\sin \theta )/(\cos \theta )`

Option c and d are correct because c is Pythagorean identity .