Sunday

December 21, 2014

December 21, 2014

Posted by **Shawn** on Wednesday, January 15, 2014 at 8:02am.

- Math -
**Reiny**, Wednesday, January 15, 2014 at 8:31amYour relation could be linear:

using (3/2 , 17,6) and (3, 13/3)

slope = (17/6 - 13/3)/(3/2 - 3) = (-3/2) / (-3/2) = 1

y - 13/3 = 1(x-3)

3y - 13 = 3x-9

3x - 3y = -4

now plug in the given input as x or the given output as y

e.g input = x = 11/4

3(11/4) - 3y = -4

times 4

33 - 12y = -16

-12y = -49

y = -49/-12 = 49/12

do the remaining one in the same way

your relation could have been quadratic:

let's make (3,13/3) the vertex

then

y = a(x-3)^2 + 13/3

but (3/2 , 17/6) lies on it

17/6 = a(3/2 - 3)^2 + 13/3

17/6 = a(9/4) + 13/3

times 12

34 = 27a + 52

27a = -18

a = -18/27 = 2/3

so it could have been

y = (2/3)(x-3)^2 + 13/3

There could have been an infinite number of possible quadratics, not to mention, we could have made it into a cubic, etc.

- Math -
**Steve**, Wednesday, January 15, 2014 at 11:24amHmmm. In general, you cannot fit a quadratic to 4 points. Only a single cubic, but many of higher degree.

- Math -
**Reiny**, Wednesday, January 15, 2014 at 11:32amSteve, only 2 points were actually given.

(3/2, 17/6)

(3, 13/3)

The others were

(0, ??)

(11/4, ??)

So I could form a unique linear, but an infinite number of quadratics, cubics, etc that pass through those two points.

Once I have an equation, the missing y values of the other 2 points are then found

- Reiny - Oww - my Bad! -
**Steve**, Wednesday, January 15, 2014 at 12:35pmOww. My Bad!

**Answer this Question**

**Related Questions**

math - i need help! my last math question cant figure out! whats the rule for ...

math - im trying to complete this input output table input 0 output blank input ...

Math - Hey, I need your help! I have an input output table that I need the ...

Algebra - I have an input / output machine I need a rule I can use for any value...

math - i need help with patterns and equations i cant find the rule it goes like...

7 th grade math - What is the rule for this function? input 1 output 3 input 2 ...

math - Please help me find the rule input 0 output 2 then input 1 output 4 next ...

calculus - i have a problem figureing out this question do you have any help? ...

math - What is the rule for this function? Input 1 output 3 Input 2 output 5 ...

math - What is the rule for this function? Input 1 output 3 Input 2 output 5 ...