Finding equation of linear function from four points given

Finding equation of linear function from four points given Patelway the only best way mathproblems

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• Finding
• equation
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• linear
• function
• from
• four
• points
• given
• Patelway
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• best
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• mathproblems

[oticon6]

You made it too easy by giving the value at x = 0. That gives away C and everyone who passed grade 8 Maths knows that gradient = rise/run.

[mathproblems]

this is the actual SAT problem

[roughneckmonkey]

That took me literally 10 seconds. I found the slope by subtracting the first two Y values and their corresponding X values.

4-2/-1-0 = -2

The slope is -2 so only E had that choice.

[mathproblems]

now you are getting smarter than the tutor the Mathninja Brown and Nerdy LOL

[ramacdo]

answer e, got through trial and error process.

[mathproblems]

in my tutoring trial and error is not allowed also no choices would be given to you remember that this has to be solved Patelway and the shortest way and quickest way possible

[0entropy]

Since the intercept is already given (f(0)= 2) you can limit your choices down to D and E. Plugging in 1 for x in both functions will then tell you which of them is the function you're looking for.

[websnarf]

The "Patel way" if I understand it is to derive the answer *then* check the choices. In this case, we just build the line directly: (f(x)-2)/(x-0)=(2-0)/(0-1) using the equal slopes approach. This leads to f(x)=2+(-2)*x.

[websnarf]

The fastest way to do this is to first look at x = 0. Here f(0)=2. Looking through the answers, only (D) and (E) have a constant 2 offset. For anwers (D) and (E) the coefficient is a straight integer, so picking x to be 0, 1 or -1 will make things easiest. In this case we have the value x = 1 available to us; f(1)=0. Pluging x = 1 into (D) we see that its -1+2=1 which is not correct, so the answer must be (E). It lots of steps, but the point is that you can do it all in your head.

[dooglus]

The equation is of the form f(x) = mx + c

substitute x=0,f(x)=2 and we get 2=c, so c is 2

substitute x=1,f(x)=0 and we get 0=m+2, so m is -2

so the answer is f(x) = -2x + 2