Question

can anyone check my answers and help with ones i have trouble in? thanx!

Answer 1

Sure, what are they?

Answer 2

http://prntscr.com/3r1f93

Answer 3

and im having trouble on this one too:/ http://prntscr.com/3r1ffz

Answer 4

Sorry, I've never leant this before. I've attempted it but didn't work out.

This is what I tried for your first question:
Inputted cos(pi/4) on calculator -> got answer.
Then, I tried inputting all the answers and comparing it. None of them matched.

Good luck - I'll be interested how you find the solution too :)

Answer 5

ok thanks for trying:)

Answer 6

your 1st question is cos(pi/4)
pi=180
so pi/4=45
so \[\cos(45)=\frac{ \sqrt{2} }{ 2 }=\frac{ 1 }{ \sqrt{2} }\]

Answer 7

so im correct:) its C?

Answer 8

yup. and for 2nd question it will be easier to solve them with the graphs of sin ans cos.

Answer 9

sorry by mistaken, i wrote pi and pi/2 incorrect. where i have written pi , it should be pi/2 and where i wrote pi/2 , it should be pi
so sin(0) is 0 , sin(pi/2)=1, sin(pi)=0 , sin(3pi/2)=-1 and sin(2pi)=0 again

Answer 10

similarly graph for cos is