यदि `cospix=x^(2)-x+(5)/(4)` है तो का मान ज्ञात करे ?

Options

A. 0
B. 1
C. `-1`
D. none of the above

Answer

d

Explanation

`cospi x=x^(2)-x+(5)/(4)`
`=x^(2)-2xx x xx(1)/(2)+(1)/(4)-(1)/(4)+( 5)/(4)`
`=(x-(1)/(2))^(2)+1gt1`
`=-1lecosexle1`
`therefore` so value of x is none of the above