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C2 quesion

otrivine

can someone solve this please

solve for 0<x<360

4sinx=3tanx
thanks

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Reply 1

xy5

Original post by otrivine

can someone solve this please

solve for 0<x<360

4sinx=3tanx
thanks

Why dont you start us off?
A nice place could be to write tan in terms of sin and cos...

Reply 2

Fazeel 123

3 Sin/cos = 4sin x
3= 4sin cos/sin (sin cancel out)
3=4cosx
cosx=3/4 Cos^-1(3/4)

Reply 3

TenOfThem

Original post by Fazeel 123

3 Sin/cos = 4sin x
3= 4sin cos/sin (sin cancel out)
3=4cosx
cosx=3/4 Cos^-1(3/4)

Firstly, it is better not to give full answers
Secondly, this is not correct as you can not cancel the sin

Reply 4

Mr M

Original post by Fazeel 123

3 Sin/cos = 4sin x
3= 4sin cos/sin (sin cancel out)
3=4cosx
cosx=3/4 Cos^-1(3/4)

Good grief. Please don't post full solutions and please don't post wrong solutions.

Reply 5

Fazeel 123

Original post by TenOfThem

Firstly, it is better not to give full answers
Secondly, this is not correct as you can not cancel the sin

What is the correct way

Reply 6

TenOfThem

Original post by Fazeel 123

What is the correct way

To wait for the OP to reply and see what he has done so that we can correct mis-conceptions and support his learning :smile:

Reply 7

Dj.Clay

And not dividing by zero :wink:

Reply 8

Mr M

Original post by Fazeel 123

What is the correct way

You divided by zero. You have to factorise.

Reply 9

xy5

Original post by Fazeel 123

What is the correct way

Whilst you wait, sketch 4sinx and 3tanx in the given interval and see if you suggestion stack up.

Reply 10

otrivine

ok i tried many times but its hard i used

tanx=sinx/cosx
in this question 4sinx=3tanx you can divide the sin with cos to give you tan but the problem is u have tan then i dont know what to do

Reply 11

Fazeel 123

There is nothing wrong with the solution and what do you factorise

Reply 12

Dj.Clay

Ooh I wouldn't change the sin into tan by dividing through by cos

In general if you have sin cos tan in the question, you want to change the tans into sin/cos

Reply 13

TenOfThem

Original post by Fazeel 123

There is nothing wrong with the solution and what do you factorise

Your solution is incorrect ... you have omitted answers

Reply 14

Fazeel 123

I got A in my C2 exam and A overall at As Maths

Reply 15

Mr M

Original post by Fazeel 123

There is nothing wrong with the solution and what do you factorise

x^2 = x

Can you solve this equation?

Reply 16

otrivine

Original post by Fazeel 123

There is nothing wrong with the solution and what do you factorise

what do i do so confuse i just did the June 2009 paper C2 and this was a 6 mark question it is difficult i need explaination pleaseeeeee mate

Reply 17

Fazeel 123

Original post by starburst92

4sinx=3tanx
4sinx=3sinx/cosx
4cosxsinx=3sinx
4cosx=3
cosx=3/4

x=41.41, 311.41 (in degrees to 2d.p)

Well done

Reply 18

otrivine

Original post by Mr M

x^2 = x

Can you solve this equation?

mate can you please explain me the question it was 6 marks not get it :frown:

Reply 19

TenOfThem

Original post by otrivine

ok i tried many times but its hard i used

tanx=sinx/cosx
in this question 4sinx=3tanx you can divide the sin with cos to give you tan but the problem is u have tan then i dont know what to do