` cos(40^(@) - theta ) - sin (50^(@) + theta )+ ( cos^(2) 40^(@) + cos^(2) 50^(@))/( sin^(2) 40^(@) + sin^(2) 50^(@))` व्यंजक के मान ज्ञात करो ।

Explanation

` cos (40^(@) - theta )- sin (50^(@) + theta ) +( cos^(2) 40^(@) + cos^(2) 50^(@)) /( sin ^(2) 40^(@) + sin^(2) 50^(@))`
` = sin[90^(@)-(40^(@) - theta)]-sin(50^(@) + theta )+( cos ^(2) 40^(@) + cos^(2) (90^(@) -40^(@)))/( sin^(2) 40^(@) + sin^(2) (90^(@) - 40^(@))" " [:' cos alpha = sin(90^(@)- alpha)]`
`= sin (50^(@) + theta )- sin (50^@ + theta ) +( cos^(2) 40^(@) + sin^(2) 40^(@))/( sin^(2) 40^(@) + cos^(2) 40^(@))=0+1=1 `