`3cos80^(@)" "co s ec10^(@)+2" "cos59^(@)" "co s ec31^(@)` का मान ज्ञात करे?

Options

A. 1
B. 3
C. 2
D. 5

Answer

d

Explanation

`3cos80^(@)co s ec10^(@)+2cos59^(@)`
`co s ec31^(@)`
then
`CosA.co s ecB=1`
`3xx1+2xx1=5`]
`rArr3cos80^(@)(1)/(sin10^(@))+2cos59^(@)(1)/(sin31^(@))`
`rArr3cos80^(@)(1)/(sin(90^(@)-80^(@))+2cos59^(@)`
`(1)/(sin(90^(@)-59^(@))`
`rArr3+2=5`