Error analysis need answer in a least a hour or so ,what is the error

Step-by-step explanation:

1) Sin² Ф = 1 - cos² Ф

So, 1 - Sin² Ф = 1 - (1 - cos² Ф)

                     = 1 - 1 + cos² Ф = cos² Ф

2) tan x = Sin x /Cos x

tan x * csc x = Sin x /Cos x  * 1/Sin x = Sinx  * 1 / cos x  * sin x

                        =1/cos x = Sec x

can you make your screen more see able?

then i might be able to .

30,40,50 is correct answer