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# Solved. watch

1. Solved.
2. 2sinx + cosx = 0
2sinx/cosx + cosx/cosx = o
2tanx + 1 = 0
tanx = -0.5
3. (Original post by WildBerry)
I'm confused how to solve 2sinx + cos x=0 ,

There isn't any identity I could use ?

I thought of making it tan, but then I can't divide both sides because the cosx has a + sign infront, so I can only subtract the cosx from both sides ?
Why not?
If you divide +cos(x) by cos(x) you get +1.
If you divide -cos(x) by cos(x) you get -1.
4. You can divide by cos(x) ^^
5. Thanks, got it now

However doing another question now why does cos^2x/cosx become only cosx ? Doesn't the bottom go into the top twice, so it'd be 2cosx/1 ?
6. What happens if you have ?
7. (Original post by Ben121)
What happens if you have ?
Oh the indices rule ? Subtract top from bottom ?
8. (Original post by WildBerry)
Oh the indices rule ? Subtract top from bottom ?
Yes,

x2 / x1

= x2-1

= x1

= x
9. Thanks all
11. (Original post by wtfCharlie)
The maths here isn't that complicated, its just my incompetence at remembering /knowing the basic methods that were used in C1 / gcse .

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