Question: theta is an acute angle of a right triangle. Find the values of the 2 other trig ratios of theta. 

cos θ = 8


After doing the work to find out what the other leg is using the Pythagorean theorum, I got a2= -63, making the missing leg an imaginary number. Am I doing something wrong? Thanks in advance.


Update: It does say that cosine=8 even though cosines can not be more than 1.

IneedHealing  Apr 25, 2017
edited by IneedHealing  Apr 27, 2017

2+0 Answers


Does the problem really say that cos θ = 8 ?


The cosine of any real angle has to be between -1 and 1 (inclusively)


... I don't know what it means if the cosine really is bigger than 1 !

hectictar  Apr 25, 2017

If we assume this is meant to be cos θ = 0.8, then sin θ = sqrt(1-0.8^2) → 0.6 and tan θ = 0.6/0.8 → 0.75


Alan  Apr 25, 2017

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