Question

Which of the following expressions is equal to tan155°?

a.) tan55°

b.) tan25°

c.) -tan25°

Answer 1

The equal expression to tan155 is -tan25.

Hope this helps :)

Answer 2

`tan (155^(\circ))= -tan 25^(\circ)`

Explanation:

Given :
`Tan 155^(\circ)`

To Find: Which of the following expressions is equal to
`Tan 155^(\circ)`

Solution:

Using identity :
`tan (180^(\circ)-x)= -tan x`

`Tan 155^(\circ)`

We can rewrite it as
`Tan (180^(\circ)-25^(\circ))`

Substitute x = 25 in identity

So,
`tan (180^(\circ)-25^(\circ))= -tan 25^(\circ)`

`tan (155^(\circ))= -tan 25^(\circ)`

Hence Option C is correct.