Friday

April 18, 2014

April 18, 2014

Posted by **gabs** on Tuesday, June 7, 2011 at 10:56pm.

x^2 + y^2 = 36

y= x+b

and then they give me an answer box

b=_________ (smaller value)

b=_________ (larger value)

i have absolutely no idea how to even begin this and what they are asking. could some please help and explain what im supposed to do with this. thanks so much!!!

- pre calc -
**Reiny**, Tuesday, June 7, 2011 at 11:20pmsub in the straight line into the circle

x^2 + (x+b)^2 = 36

x^2 + x^2 + 2bx + b^2 - 36 = 0

for one solution the discriminant, that is

b^2 - 4ac = 0

(2b)^2 - 4(2)(b^2-36) = 0

4b^2 - 8b^2 + 288=-

-4b^2 = -288

b^2 = 72

b = ± √72 or ± 6√2

- pre calc -
**Mgraph**, Tuesday, June 7, 2011 at 11:37pmDraw two tangents to the circle x^2+y^2=6^2 parallel to the line y=x in the second and fourth quadrants.

b is y-intercept of these tangents.

Сonsider the algebraic method.

Find the coordinates of common points of the line and circle:

x^2+(x+b)^2=36

2x^2+2bx+b^2-36=0

Since the line is tangent then the equation has unique solution =>

the discriminant (2b)^2-4*2(b^2-36)=0

4b^2-8b^2+288=0

b^2=72

b=6sqrt(2) or b=-6sqrt(2)

- pre calc -
**Mgraph**, Tuesday, June 7, 2011 at 11:52pmConsider the geometric method.

b(b>0)- is the leg in a isosceles rectangular triangle with height=6

6^2+6^2=b^2

**Related Questions**

PRE CALC - Use matrices to solve the system. (If the system has infinitely many ...

CHEMISTRY (WEBWORK) - SPARTAN: Enter the numerical energy values (X, Y, & Z) on ...

calc - analyze the function ln x = cx^2 to find the unique value of c such that ...

pre calc - find the exact solution algebraically and check it by substituting ...

Pre-Calc - An open box with a volume of 1500cm^3 is to be constructed by taking ...

math - two systems of equations are giving below for each system choosethe best ...

Pre Algebra - equations of the system Ax-4y=9, 4x+By=-1 explain how to find the ...

Pre-Calc - Can you show me how to find the rectangular equation of r=2costheta...

Pre-cal - 1) Find two values of Q that satisfy the equation. Give your answer ...

algebra - Consider the following system of inequalities: {(c-1)x^2+2cx+c+4<0...