SOLUTION: given cos(2a)=-17/18 and
0<2a< pi/2
find exact values
of the six trigonometric functions.
Note: you cannot us decimals in your answer
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-> SOLUTION: given cos(2a)=-17/18 and
0<2a< pi/2
find exact values
of the six trigonometric functions.
Note: you cannot us decimals in your answer
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Question 632146: given cos(2a)=-17/18 and
0<2a< pi/2
find exact values
of the six trigonometric functions.
Note: you cannot us decimals in your answer Answer by solver91311(24713) (Show Source):
First thing to note is that since , a simple division operation shows that , forcing to be a first quadrant angle, hence all six basic trigonometric functions will be positive.
So
Since we know that
And then a little algebra music, Sammy:
From which we discard the negative root because of the interval analysis earlier to get:
And likewise:
From which we get:
Use the following identities to get the other four functions:
John
My calculator said it, I believe it, that settles it
