# Answer to Question #23146 in Trigonometry for Chris Marshall

Question #23146

Use the double angled formula to prove the following expressions.

(i) Given that cos(x+30)=3cos(x-30), prove that tanx= - root 3/ 2

(ii)prove that 1-cos2x/sin2x = tan x

(iii) verify that x= 180 is a solution of the equation 2x=2-2cos2x

(iv) Using the resulat from part (ii) or otherwise find the two other solutions 0<x<360 of the equation 2x= 2-2cos2x

Thanks

(i) Given that cos(x+30)=3cos(x-30), prove that tanx= - root 3/ 2

(ii)prove that 1-cos2x/sin2x = tan x

(iii) verify that x= 180 is a solution of the equation 2x=2-2cos2x

(iv) Using the resulat from part (ii) or otherwise find the two other solutions 0<x<360 of the equation 2x= 2-2cos2x

Thanks

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