If `sin(theta)-cos(theta)=(1)/(2)` then the value of `sin(theta)+cos(theta)` is

Options

A. `-2`
B. `pm2`
C. `(sqrt7)/(2)`
D. 2

Answer

c

Explanation

इस प्रश्न में (-) के साथ स्थान पर (+) का Sign होना चाइये था परन्तु SSC ने यह सवाल गलत हे दिया है
`x cos theta-ysin theta=sqrt(x^(2)+y^(2))` .......(i)
`rArr(cos^(2)theta)/(a^(2))+(sin^(2)theta)/(b^(2))=(1)/(x^ (2)+y^(2))` ......(ii)
`(x)/(sqrt(x^(2)+y^(@)))cos theta+(-y)/(sqrt(x^(2)+y^(2)))sin theta=1`
(from eq:(i))
`rArr sin theta=(-y)/(sqrt(x^(2)+y^(2))`
put value in eq. (ii)
`therefore (cos^(2)theta)/(a^(2))+(sin^(3)theta)/(b^(2))=(1)/(x^(2)+y^(2))`
`rArr (x^(2))/((x^(2)+y^(2))a^(2))+(y^(2))/((x^(2)+y^(2))b^(2))=(1)/(x^(2)+ y ^(2))`
`rArr (x^(2))/(a^(2))+(y^(2))/(b^(2))=1`