Answer the following:\tFind the value ofEvaluatecos 15o –sin 15oIfwhere α and β are acute angles, show thatThe circular measures of two angles of a triangle are½ and 1/3 , find the third angle in English system[ ans : 132o 16’ 22’’ ]\tA circular wire of radius 3 cm iscut and bentso as tolie along a circle of radius48cm.Find the angle subtended by the wire at the centre of the circle[ans : 22.5o]Find the angle between the hands of a clock at 7:20 P.M.[ ans: 100o]\tIfIf sec x + tan x= 4 , find sin x and cos x. Also find the quadrant in which x lies.[ ans : sin x = 15/17 , cos x == 8/17 ,First ]\tIfIf tan A + cot A = 2, then find tan100A + cot100A[ans : 2 ]Prove thatProve that tantantantantan= 1Prove that cos+cos+cos=Prove that sin 10 osin 50o sin 70 o=Prove that cos10o cos 30o cos 50ocos 70 o=Prove that+ += 0\tIf cosx +cosy=and sinx+siny =tan\tProve thatProve that= tanx\tProve that cos 5x = 16cos 5 x -20 cos 3 x +5cosx\tSolve the equation cosx + sin x = cos2x + sin2x\tFind all values of A between 0o and 720o which satisfy the equation2 cos2A -5cosA+ 2 = 0[ans :60 o, 300 o, 420 o, 660 o]\tFind the value of sin2x, sin, cos2x, cosif, cos x = , x lies in third quadrant.\tFind the principal and general solution of\t2sinx + 1 = 0(b) sin x + cos x=0\tFind the general solutionsfor the followinga) sin 2x + sin4x + sin6x = 0b) 2cos2x + 3sinx = 0c) cos x + cos3x = 2 - 4sin2xd) cos x – sin x =e)sec x + tan x = 1

aditya gupta , 9 Years ago

Grade 11