Question

how do i solve cos2x-cosx=0 where the interval is 0 (less than or equal to) x (less than or equal to) 2 pi

Answer 1

can you change the cos2x into something different?

Answer 2

x= pi/2

Answer 3

@fibonaccichick66 i dont think so

Answer 4

and @SanjanaP how did you get that

Answer 5

Have you learned double angle identities?

Answer 6

if not, I recommend looking that up to begin

Answer 7

i have the formulas for double angle identities yes

Answer 8

that is how you get rid of the 2x to begin

Answer 9

have u learned the double angle formulas, cause thats how we can start

Answer 10

so please, re-write the eq, using it

Answer 11

im not sure how to apply the formulas to this problem. if you dont mind, can you explain it?

Answer 12

well, what does cos2x=? by definition

Answer 13

2sinxcosx

Answer 14

for cosine?

Answer 15

better check this http://www.purplemath.com/modules/idents.htm

Answer 16

check that website out it has a lot of amazing features