Tuesday

January 27, 2015

January 27, 2015

Posted by **Jake** on Saturday, April 7, 2012 at 1:35pm.

a) 2x + 3y - 7=0, -3x - 2y + 2=0

b) 2x - 3y + 2=0, 5x - 7y + 2=0

c) -4x + y - 3=0, x + 4y=0

d) -5x + y + 1=0, 5x + y + 1=0

Please explain. I know we have to use the dot product :3

- Calculus -
**Reiny**, Saturday, April 7, 2012 at 2:59pmfor any ax + by + c = 0 , the direction vector of the normal is (a,b)

If the normals are perpendicular, then obviously the line are perpendicular, so ...

a)

normal to first line is (2,3)

normal to 2nd line is (-3,-2)

dot product = -6 - 6 ≠ 0

so the lines are NOT perpendicular.

do the others the same way.

If you get a dot product of zero , they are perpendicular.

**Answer this Question**

**Related Questions**

geometry - Martin drew a pair of perpendicular lines and a pair of parallel ...

math - Find the slope of the lines that are (a) parallel lines (b) perpendicular...

math - Find the slope of the lines that are (a) parallel lines (b) perpendicular...

Geometry - If two non parallel lines are perpendicular to two other straight ...

algebra - Is the following pair of lines paralle or perpendicular? Prove the ...

PLease check math - 1)Find an eauation of the line containing the given pair of ...

math help please - Tell whether the lines for each pair of equations are ...

geometry - Wendy drew line segment LM. She used a compass and straightedge and ...

MATH - Post your 50 or more word response to the following in the assignment ...

Math - 38. Tell whether the lines for the pair of equations are parallel, ...