Fundamental law of trigonometry is given by cos (x + y) = cos x cos y____sin x sin y____? If O is added or subtracted from an even multiple of /2, the trigonometric ratios shall remain the same? If is added or subtracted from odd multiples of right angle, the trigonometric ratios change into ? If an angle is greater than 3 /2 and less than 2 , its terminal ray lies in ?P is a point on the terminal side of an angle one unit away from origin; the co-ordinates of P are?

If Sin x = ½, Cos y = 1/3 the value of Cos (x + y) = __________? If is in first quadrant then sign of tan (2 - ) is __________? Reduce sin 4 to an expression involving only function of multiples of as unity? Without using calculator find tan 750? Express 3sin + 4cos in the form r sin ( + ) where the terminal side of O is in Ist quadrant?