Question #d3a7a

2 Answers
Nov 29, 2016

Solution: x=31.7^0(1dp) and x=121.7^0(1dp)x=31.70(1dp)andx=121.70(1dp)

Explanation:

sin2x=2cos2x or (sin2x)/(cos2x)=2 or tan2x=2 or 2x= tan^-1 2 =63.4349^0:. x=31.7^0(1dp) and since tan(pi+2x)=tan2x=2 :. 2x=180+63.4349=243.439^0:.x=121.7(1dp)

Solution: x=31.7^0(1dp) and x=121.7^0(1dp)[Ans]

Nov 29, 2016

sin2x=2cos2x

=>tan2x=2=tan^-1(2)=alpha

So 2x=npi+alpha," where " n in ZZ

x=(npi)/2+alpha/2=(npi)/2+31.7^@

by calculator, alpha =tan^-1(2)= 63.4^@