4.3 Point-Slope Review

4.3 Point-Slope Review

Slope - Intercept Form

the original one

y=mx+b

Good if it hits the y-axis

on a whole number.

Point - Slope form

new one

y-y₁=m(x-x₁)

Good if it hits the y-axis in the middle. Like a decimal or fraction.

Multiple Choice

Which one is Point-Slope form?

• $y=mx+b$

• $y-y_1=m\left(x-x_1\right)$

Multiple Choice

Which one is Slope-Intercept Form

• $y=mx+b$

• $y-y_1=m\left(x-x_1\right)$

Multiple Choice

Which form would you use?

• $y=mx+b$

• $y-y_1=m\left(x-x_1\right)$

Multiple Choice

Which form would you use?

• slope-intercept

• point-slope

Multiple Choice

Point Slope Form

 $y-y_1=m\left(x-x_1\right)$  

Find the equation of the line through (5,6) and slope = 7

• y+6=7(x+5)

• y+5=7(x+6)

• y-6=7(x-5)

• y+5=7(x+6)

Multiple Choice

Point Slope Form

 $y-y_1=m\left(x-x_1\right)$  

Find the equation of the line through (-3,-1) and slope = -2/5

• y+1=-2/5(x+3)

• y+3=-2/5(x+1)

• y-1=-2/5(x-3)

• y+3=-2/5(x+1)

Multiple Choice

What is the slope of the line

 $y=-2x-3$  

• 2

• -2

• 3

• -3

Multiple Choice

What is the slope of the line

 $y-5=4\left(x+2\right)$  

• 2

• 4

• 5

Parallel lines are two lines that never touch. They go in same direction.

Same slope

Multiple Choice

True or False?

Parallel lines have the same slope?

• True

• False

Multiple Choice

What is the equation of a line parallel to y=2x+3 and goes through the point (4,5)

• y-2=3(x-4)

• y-4=3(x-5)

• y-5=2(x-3)

• y-4=2(x-5)

Perpendicular Lines make a right angle. They have opposite reciprocal slopes.

We have to change slope.

Remember flip it and switch signs

Multiple Choice

What is opposite reciprocal of 3/5?

• 3/5

• 5/3

• -5/3

Multiple Choice

What is opposite reciprocal of -2?

• 2

• 1/2

• -1/2

Multiple Choice

What is a line perpendicular to y=3/4x+10 and through point (5,6)?

• y-6=3/4(x-5)

• y-6=-3/4(x-5)

• y-6=4/3(x-5)

• y-6=-4/3(x-5)