[FONT="Arial"]Find the equation of the bisector of the acute angle whose equation is

and

Attempt

L1=

L2=

Since, the bisect line is in the middle of the lines then we use the formula

=

Is my answer correct?

Thank you.

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- June 27th 2009, 12:13 AMmj.alawamiBisector of an acute angle Q2 (Help)
[FONT="Arial"]Find the equation of the bisector of the acute angle whose equation is

and

__Attempt__

L1=

L2=

Since, the bisect line is in the middle of the lines then we use the formula

=

Is my answer correct?

Thank you. - June 27th 2009, 04:13 AMearboth
- June 27th 2009, 04:16 AMmj.alawami
- June 27th 2009, 04:35 AMearboth
- June 27th 2009, 04:39 AMSoroban
Hello, mj.alawami!

Your game plan is correct,

but you have some incorrect minus-signs.

Quote:

Find the equation of the bisector of the acute angle whose equation is:

. . and

__Attempt__

. ??

There is no minus-sign in the denominator.

Since, the bisect line is in the middle of the lines,

then we use the formula: . ??

The distances are of*opposite*signs?

=

Is my answer correct? . . . . Sorry, no

But you were close . . .

Try it again without those extra minus-signs.

- June 27th 2009, 07:28 AMpankaj
Here is a general method which I have been using.

Let the two lines be

Remember to write the two equations in such a way that and .

The eqution of the bisectors are

If ,then use of sign in above equation will give OBTUSE angle bisector

i.e.

is eqution of OBTUSE angle bisector and

gives equation of ACUTE angle bisector

.................................................. .................................................. ..

If ,then use of sign in above equation will give OBTUSE angle bisector

i.e.

is eqution of OBTUSE angle bisector and

is equation of ACUTE angle bisector

.................................................. .............................................

__General rule__

(i)

where,

(ii)Find sign of

(iii)The use of this sign always gives the OBTUSE angle bisector and the use of other sign gives ACUTE angle bisector