Plz solve the problem as mention in the abovequestion no.7

U can write as asinx = bcosx = ctan2x = t it can be solved by 2 method , first take any value of x where all three all defined i.e. I take x=30° then a=2t , b=2t/√3 c=t/√3,then Put value of a,b,cin equation and t will cancel out from both sides and u will get value of k=4, otherwise convert all into half angles of tan then u will also got the same thing..