" 38.If "x sin alpha=y cos alpha," prove that "(x)/(sec2 alpha)+(y)/(cosec2 beta)=xquad [" B.U.54] "

If x sin alpha=y cos alpha, prove that :(x)/(sec2 alpha)+(y)/(cos ec2 alpha)=x

If x sin alpha = y cos alpha, prove that : x/(sec 2alpha) + y/(cosec 2 alpha) = x

If x sec alpha+y tan alpha=x sec beta+y tan beta=a , then sec alpha*sec beta=

If x= sin alpha + sin betga , y = cos alpha + cos beta tan alpha + tan beta =

If tan alpha = (x sin beta)/(1-x cos beta) " and " tan beta = (y sin alpha)/(1-y cos alpha),"show that", (sin alpha)/(sin beta) = x/y .

If tan theta = (x sin alpha + y sin beta)/(x cos alpha + y cos beta), "prove that " x sin (theta - alpha) + y sin (theta - beta) = 0

If x = sin alpha, y = sin beta, z = sin (alpha + beta) then cos (alpha + beta) =

If x cos alpha + y sin alpha = x cos beta + y sin beta = 2a then cos alpha cos beta =

"If "0ltalphaltpi/2 " and " sin alpha + cos alpha + tan alpha + cot alpha + sec alpha + cosec alpha = 7 " then " "show that " sin 2 alpha " is a root of " x^(2) - 44x - 36 = 0