The following expression was simplified incorrectly In which

The following expression was simplified incorrectly. In which line error first made when simplifying the identity shown below? 1 + sec(-theta)/sin(-theta) + tan(-theta) = 1 - sec theta/sin theta - tan theta = 1 - sec theta/sin theta [1 - (1/cos theta)] = 1 - sec theta/sin theta (1 - sec theta) = 1/sin theta = csc theta

Solution

we know that sin(-theta) = -sin (theta )

hence the mistake was first identified in the line 1