How do you write an equation of a line given (1,-3) and (-2,-4)?
1 Answer
Jun 17, 2017
Explanation:
#"the equation of a line in "color(blue)"slope-intercept form"# is.
#color(red)(bar(ul(|color(white)(2/2)color(black)(y=mx+b)color(white)(2/2)|)))#
where m represents the slope and b the y-intercept.
#"to calculate m use the" color(blue)" gradient formula"#
#color(red)(bar(ul(|color(white)(2/2)color(black)(m=(y_2-y_1)/(x_2-x_1))color(white)(2/2)|)))#
where# (x_1,y_1),(x_2,y_2)" are 2 points"#
#"the points are " (x_1,y_1)=(1,-3),(x_2,y_2)=(-2,-4)#
#rArrm=(-4-(-3))/(-2-1)=(-1)/(-3)=1/3#
#rArry=1/3x+blarr" is partial equation"#
#"substitute either of the 2 points into the partial equation"#
#"to obtain b"#
#"using " (1,-3)#
#-3=1/3+brArrb=-3-1/3=-10/3#
#rArry=1/3x-10/3larrcolor(red)" in slope-intercept form"#
