when the angle (say) theta is negative,
1) sin (-θ) = - sin θ
2. tan (-θ) = - tan -θ
then why,
3. cos (-θ) = cos θ? Could you explain this point here, please? I am confused.
when the angle (say) theta is negative,
1) sin (-θ) = - sin θ
2. tan (-θ) = - tan -θ
then why,
3. cos (-θ) = cos θ? Could you explain this point here, please? I am confused.
Think about what you learned back in algebra about even and odd functions.... (here)
I understand it. Thank you all.
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