Question

how do i do this problem find the exact solution of the expression sec^2pi/3-8

Answer 1

\[\sec^2(\frac{\pi}{3})-8\]?

Answer 2

yes exactly

Answer 3

first find \(\cos(\frac{\pi}{3})\)
do you know it ?

Answer 4

but the directions say i would be able to do it without a calculator but i got .99983

Answer 5

ooops

Answer 6

take your calculator out of degree mode, put it in radian mode
then it will give you the correct answer

Answer 7

but in any case it would not hurt to know that
\[\cos(\frac{\pi}{3})=\frac{1}{2}\]

Answer 8

you can see it from the unit circle
do you have a good unit circle cheat sheet?

Answer 9

you do now
in any case secant is the reciprocal of cosine
the reciprocal of \(\frac{1}{2}\) is \(2\)
square it, subtract 8 and you are done

Answer 10

so -4?

Answer 11

yes

Answer 12

thank you !!!!

Answer 13

yw

Answer 14

will you help me with another one ?

Answer 15

sure