Question

Solve, 2costheta-1=0, if 0 12 years ago

Answer 1

2 cos theta= -1
=1/2
theta = 60 or theta = 300 degrees
can someone verify, thx.

Answer 2

Is your first line supposed to be 2 cos theta= +1 (instead on minus 1?)

Answer 3

no

Answer 4

First line in your solution.

Answer 5

2 cos theta -1 = 0

Answer 6

theta = 60 or theta = 300 degrees is correct.

Answer 7

thanks! you are brilliant

Answer 8

2sin^2x+3sinx-2=0, if 0<x<2pi

Answer 9

You did all the work correctly in all three problems. I am just verifying what you have already done correctly. Kudos to you.

Answer 10

I came up witth -pi/6 & 7pi/6
or
-30 degrees and 210 degrees

Answer 11

I am getting sin(x) = 1/2
or x = 30 or 150 degrees

Answer 12

ok

Answer 13

w x between 0 and 2 pi?

Answer 14

ya you're right actually... i made a careless mistake

Answer 15

(2sin(x)+1)(sin(x)-2=0

Answer 16

2sin^2x+3sinx-2=0
2sin^2x+4sinx - sinx -2=0
2sinx(sinx + 2) - 1(sinx+2) = 0
(2sinx-1)(sinx+2) = 0
sinx = 1/2 or sinx = -2 (which is not possible)
So sinx = 1/2
x = 30 or 150 degrees and both fall in the domain 0<x<2pi

Answer 17

so sin x=1/2 with x at 30 or 150

Answer 18

Yes.

Answer 19

sin x-cos x=1, if 0<x<2pi
i got x=pi/2 , 3pi/2 or x=pi

Answer 20

I have to go now. But you seem to know your stuff and so you will do fine.

Answer 21

thanks

Answer 22

sin x-cos x=1, if 0<x<2pi
x = pi/2 or x = pi
The other solution you got x=3pi/2, if you put it back in the original equation
sinx - cosx = 1 you will notice it does not satisfy the equation. It gives -1. The reason is because you probably squared both sides and so it will satisfy the squared equation but not the original equation and so you discard them.