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Math Analysis Question

I forget what this is called but can someone just explain how to do this type of problem?

arccos(tan1/2)

I know you can do this by making a triangle for the one in perentheses but I'm confused how to know whether the triangle goes in the I, II, III, or IV Quadrant? Someone please explain I'm a bit confused with this

November 13, 2012

6 Comments • Newest first

bombinator

Are you sure you wrote the question correctly? You won't be able to solve arccos(tan1/2) without a calculator

Reply November 13, 2012
Herms

[quote=qtip97]I forget what this is called but can someone just explain how to do this type of problem?

arccos(tan1/2)

I know you can do this by making a triangle for the one in perentheses but I'm confused how to know whether the triangle goes in the I, II, III, or IV Quadrant? Someone please explain I'm a bit confused with this[/quote]

All numbers in tangent are positive which makes it assume that it's in the first quadrant. If the numerator was negative, then it would be in the 4th quadrant. If the denominator was negative, then it would be in the 2nd quadrant. If both are negative, then it would be in the 3rd quadrant

Reply November 13, 2012 - edited
cchpm

[quote=xdwow]@cchpm, it's probably possible to do without a calculator, but you need to know trig identities which I never memorize myself.[/quote]

no, you would need some kind of pi in order to solve it without a calculator.

Reply November 13, 2012 - edited
xdwow

@cchpm, it's probably possible to do without a calculator, but you need to know trig identities which I never memorize myself.

Reply November 13, 2012 - edited
radkai

Quadrant 1: all
2: sine
3: tangent
4: cosine

Reply November 13, 2012 - edited
cchpm

You can't solve for tan1/2 without a calculator.

Reply November 13, 2012 - edited