Question

find the acute angle between the lines x+2y=7 and 5x-y=2

Answer 1

I did\[\tan^{-1} \left( 5 \right)=78.69 degrees\]

Answer 2

and \[\tan^{-1} \left( -.5 \right)=-26.75 degrees\]
so arent yu supposed to subtract that from 180 to get 153.43 degrees

Answer 3

then you subtract 153.43 degrees from 78.69 degrees to get 75.74 degrees?

Answer 4

can anyone tell me if this is correct?