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Which of the following are identities? Check all that apply.

Which of the following are identities? Check all that apply.-example-1
User Patryce
by
5.3k points

2 Answers

2 votes

Answer:

Option B and Option D.

Explanation:

Among the options, only B and D represent identities, they are known has pythagorean identities because they are obtained form a right triangle and its trigonometry.

All pythagorean identities are


sin^(2)\alpha+cos^(2) \alpha =1


tan^(2)\alpha +1=sec^(2)\alpha


cot^(2) \alpha +1=csc^(2) \alpha

If you compare only B and D represent two of these identities.

Option A and C don't represent identities because they are written wrong, if you compare with all three identities above, you will realize this.

Therefore, the right options are B and D.

User Edward Chan
by
5.5k points
4 votes

Answer: Option 'B' and 'D' are correct.

Explanation:

Since we know the trigonometric identities as follows :


\sin^2x+\cos^2 x=1\\\\\sec^2 x-\tan^2 x=1\\\\cosec^2 x-\cot^2 x=1

According to options , we get that


cosec^2 x=1+\cot^2 x satisfies the identities.

and
\sin^2x+\cos^2 x=1 is the identity.

Hence, Option 'B' and 'D' are correct.

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