त्रिकोणमितीय सारणी का प्रयोग किये बिना मान ज्ञात कीजिए :
`(cot(90^(@) -theta)* sin(90^(@) - theta))/(sin theta) + (cot 40^(@))/( tan 50^(@)) - (cos^(2) 20^(@) + cos^(2) 70^(@))`

Explanation

`(cot(90^(@) -theta)* sin(90^(@) - theta))/(sin theta) + (cot 40^(@))/( tan 50^(@)) - (cos^(2) 20^(@) + cos^(2) 70^(@))`
`= ( tan theta * cos theta)/( sin theta) + (cot 90^(@) - 50^(@))/(tan 50^(@)) - { cos^(2) (90^(@) - 70^(@)) + cos^(2) 70^(@)}`
` = ( sin theta * cos theta)/( cos theta * sin theta) + (tan 50^(@))/(tan 50^(@)) - ( sin^(2) 70^(@) + cos^(2) 70^(@))`
`= 1 + 1 -1 = 1`