SOLUTION: I have to find the exact trigonometric expression for: sec (30º) - cos(7π/4)= please??? :(

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Question 1029883: I have to find the exact trigonometric expression for: sec (30º) - cos(7π/4)=
please??? :(
Answer by ikleyn(52817) About Me  (Show Source):
You can put this solution on YOUR website!
.
I have to find the exact trigonometric expression for: sec (30^0) - cos(7π/4)=
please??? :(
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sec(30°) = 1%2Fcos%2830%5Eo%29 = 1%2F%28%28sqrt%283%29%2F2%29%29 = 2%2Fsqrt%283%29 = %282%2Asqrt%283%29%29%2F3.


cos%287pi%2F4%29 = cos%28pi%2F4%29 = sqrt%282%29%2F2.


sec (30°) - cos(7π/4) = %282%2Asqrt%283%29%29%2F3+-+sqrt%282%29%2F2 = %284%2Asqrt%283%29%29%2F6+-+%283%2Asqrt%282%29%29%2F6 = %284%2Asqrt%283%29+-+3%2Asqrt%282%29%29%2F6.