Question

What is the slope of a line perpendicular to the line with equation y = 4x + 5?

Answer 1

hmm what's the slope of " y = 4x + 5 " you think?

Answer 2

uhhhh 4

Answer 3

?

Answer 4

yes so
the slope of a line perpendicular to that one, will have a NEGATIVE RECIPROCAL slope
that is \(\bf {\color{blue}{ 4}}\implies \qquad negative\implies -\cfrac{{\color{blue}{ 4}}}{1}\qquad reciprocal\implies -\cfrac{1}{{\color{blue}{ 4}}}\)

Answer 5

thanks

Answer 6

yw