Question

Please Help! Will fan and medal
Find an equation for the line that passes through (–3, 8) and perpendicular to y =-1/4x -3

Answer 1

hmmm what's the slope of -> =-1/4x -3 you think?

Answer 2

-1/4

Answer 3

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

so you're really being asked to find the equation of a line with a slope of "4" and that passes through (-3, 8)

thus \(\bf \begin{array}{lllll}
&x_1&y_1\
&({\color{red}{ -3}}\quad ,&{\color{blue}{ 8}})\quad
\end{array}
\\\quad \\

slope = {\color{green}{ m}}= 4
\\ \quad \\

y-{\color{blue}{ y_1}}={\color{green}{ m}}(x-{\color{red}{ x_1}})\qquad \textit{plug in the values and solve for "y"}\\
\qquad \uparrow\\
\textit{point-slope form}\)

Answer 4

hmm anyhow \(\bf \begin{array}{lllll}
&x_1&y_1\\
&({\color{red}{ -3}}\quad ,&{\color{blue}{ 8}})\quad
\end{array}
\\\quad \\

slope = {\color{green}{ m}}= 4
\\ \quad \\

y-{\color{blue}{ y_1}}={\color{green}{ m}}(x-{\color{red}{ x_1}})\qquad \textit{plug in the values }\\
\qquad \uparrow\\
\textit{point-slope form}\)

well, you're not asked to set it in slope-intercept form.... so you can just leave it like that in point-slope anyhow

Answer 5

Thanks :D

Answer 6

yw