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1. Hi,

I have a question on my FSMW Additional Maths paper that I just can't seem to get my head around .

Find the values of x in the range 0<x<360 (degrees) satisfying the equation :

4sinx = 3cosx .

Now, I thought tanx=sinx/cosx so I did 4/3 to get 1.33 and then put in tan-1(1.33 but after having a look on the markscheme this is their answer

4sinx−3cosx= 0 ⇒

sinx/cosx = 3/4 ⇒ tanx=0.75 ⇒ tan-1(0.75 then all the relevant values.

Now where I get confused is, sinx/cosx is 4/3 surely and I don't understand how they have switched it to make 4 the denominator and 3 the numerator?

Thanks

2. Hi,

Thanks but that still doesn't make any sense?

I thought tanx=sinx/cosx

therefore 4sinx/3cosx would equal tanx 4/3?
3. (Original post by abcmaths)
Hi,

Thanks but that still doesn't make any sense?

I thought tanx=sinx/cosx

therefore 4sinx/3cosx would equal tanx 4/3?
4sinx = 3cosx
sinx = 3/4cosx
sinx/cosx = 3/4
tanx = 3/4
4. Thanks I completely understand it now

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