`x=a" "sectheta" "cosphi,y=b" "sectheta" "sinphi,Z=c" "tantheta,` है तो `(x^(2))/(a^(2))+(y^(2))/(b^(2))-(z^(2))/(c^(2))` का मान क्या होगा?

Options

A. 1
B. 4
C. 9
D. 0

Answer

a

Explanation

`x=a sec thetacos phi`
`y=b sec theta sin phi`
`z=c tan theta`
`(x)/(a)=sec theta.cos phi`
`(y)/(b)=sec theta. Sin phi`
`(z)/(c)=tan theta`
`therefore(x^(2))/(a^(2))+(y^(2))/(b^(2))-(z^(2))/(c^(2))`
`rArrsec^(2)theta.cos^(2)phi+sec^(2)theta.sin^(2)phi-tan^(2)theta`
`rArrsec^(2)theta(cos^(2)phi+sin^(2)phi)-tan^(2)theta`
`rArrsec^(2)theta-tan^(2)theta=1`