## anonymous one year ago all lines whose slopes and x intecept equal Ans. y=y'x-y'^2

1. anonymous

help

2. amoodarya

what you have tried ?

3. anonymous

$y=mx+b$

4. anonymous

y=bx+b y'=b

5. anonymous

subst. y=y'x+y' factor out

6. anonymous

y=y'(x+1)

7. anonymous

what is the next step ? @amoodarya

8. ganeshie8

Looks you're wrongly assuming $$b$$ is the x intercept

9. ganeshie8

For a straight line, $$y = mx + b$$, the x intercept can be worked by plugging in $$y=0$$ : $0 = mx+b \implies x = -\frac{b}{m}$

10. ganeshie8

therefore $$-\frac{b}{m}$$ is the x intercept, not $$b$$

11. ganeshie8

Since you want that equal to the slope, $$-\frac{b}{m}=m \implies b=-m^2$$ and the equation of line becomes : $y = mx-m^2$ plugin $$m=y'$$ and you're done!

12. anonymous

@ganeshie8 thank you , i did it :)

13. anonymous