How do you find the value of cot90?

1 Answer
Jul 11, 2015

cot(90)=0

Explanation:

Recall that cot(θ)=1tan(θ)

and that tan(θ)=sin(θ)cos(θ)

So,

cot(θ)=1tan(θ)=1sin(θ)cos(θ)=cos(θ)sin(θ)

Now, let's just put in 90 degrees for θ

cot(θ)=cos(θ)sin(θ)

cot(90)=cos(90)sin(90)

Recall, from the unit circle (below) that sin(90)=1 and cos(90)=0:

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So,

cot(90)=cos(90)sin(90)

cot(90)=01=0