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trig

Given that
5cosx - 2sinx =0
show that
tanx = 2.5
did you get that question from the internet?
Reply 2
Avatar for Notnek
Notnek
21
Original post by Katiekat2000
Given that
5cosx - 2sinx =0
show that
tanx = 2.5

You can divide the whole equation by cos(x), or if you prefer you can first move the 2sin(x) to the right of the equation and then divide both sides by cos(x).
Reply 3
Avatar for Kyx
Kyx
6
Original post by Katiekat2000
Given that
5cosx - 2sinx =0
show that
tanx = 2.5


Sinx/cosx = tanx
Original post by mosisgansta
did you get that question from the internet?

from a homework paper
Divide by cos or sin
Original post by notnek
You can divide the whole equation by cos(x), or if you prefer you can first move the 2sin(x) to the right of the equation and then divide both sides by cos(x).


so i got 5cosx/cosx = 2sinx/cosx
i get 2sinx/cosx = 2tanx
but what happens to the other side?
does that turn to 5 and then you divide that by 2 to get the tan x on it's own giving you 2.5?
Reply 7
Avatar for Notnek
Notnek
21
Original post by Katiekat2000
so i got 5cosx/cosx = 2sinx/cosx
i get 2sinx/cosx = 2tanx
but what happens to the other side?
does that turn to 5 and then you divide that by 2 to get the tan x on it's own giving you 2.5?

Yes that's right.

5cos⁡xcos⁡x\displaystyle \frac{5\cos x}{\cos x}

The cos⁡x\cos x cancels to give

51=5\displaystyle \frac{5}{1} = 5
Original post by notnek
Yes that's right.

5cos⁡xcos⁡x\displaystyle \frac{5\cos x}{\cos x}

The cos⁡x\cos x cancels to give

51=5\displaystyle \frac{5}{1} = 5

thanks so much :smile:

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