5-2B Two-Point Equation of a Line Warm-up (IN) Learning Objective: to determine the equation of a line through 2 given points. Rewrite the equations in slope-intercept form and identify m and b. m = -4/5 b = 1 m = -1/3 b = 4 m = -1 b = -1/8 m = 8 b = 0
Notes Learning Objective: to determine the equation of a line through 2 given points. Ex 1 – Write the equation of the line through the points a. (-2,-1) and (2,3) 1 st – find the slope y=mx+b Need m and b! 3-(-1) 2-(-2) = 4 = nd – substitute slope into y=mx+b y= 1 x +b 3 rd – pick a point to substitute for x and y 3= 1 (2) +b 3= 2 +b 4 th – solve for b -2 1 =b 5 th – plug m and b back into y=mx+b y= x +1
Learning Objective: to determine the equation of a line through 2 given points. b. (1,6) and (3,-4) = = -5 y= -5x +b 6= -5 (1) +b 6= -5 +b =b y= -5x +11
Learning Objective: to determine the equation of a line through 2 given points. c. (64,-32) and (52,-28) -28-(-32) = = y= x +b -28= (52) +b -84= b =3b y= =b 3 x
HW – pg. 341 #21-28 Out – write the equation through Summary – I think I understand… POW!! (-5,2) and (-6,0)