Find all the solutions, in the interval 0<= x <2pi, of the equation (1-tanx)(2sinx+1)=0, giving each solution in terms of pi.
^ This question is from the Pearson AS maths workbook.
The identities we can use are tanx= sinx/cosx and cos2x+sin2x=1
The answers are pi/4, 5pi/4, 7pi/6 or 11pi/6
I can't seem to get the expanded equation in terms of just one trig... could I have some help with this please? I think I'll be okay finding the solutions but it's the identities that are causing me issues (as we've still not been taught this, two weeks before c2!)
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Trig identities question watch
- Thread Starter
- 09-05-2015 18:56
- 09-05-2015 21:01
I don't think you need to use identities for this question. Just work out the solutions for tanx=1 and sinx=-1/2 in the interval of 0<=x<2pi.