sykhan
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Can any one help me plz to solve y= ab^x if two points are ( 2,8) (0.5, 1)
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RDKGames
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(Original post by sykhan)
Can any one help me plz to solve y= ab^x if two points are ( 2,8) (0.5, 1)
Well from those two points you are able to get two equations in a and b by simply substituting the coordinates into it. Try that.
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the bear
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so let y = 8 and x = 2

then repeat for the other coordinates.
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DFranklin
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Taking logs might make things easier...
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ghostwalker
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I'd form the two equations, and divide one by the other - doesn't even need a calculator.
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sykhan
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When i divide both equation i got b^1.5= 8 now i dont know how to get rid of this decimal power. Plz help me
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ghostwalker
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(Original post by sykhan)
When i divide both equation i got b^1.5= 8 now i dont know how to get rid of this decimal power. Plz help me
Square the whole thing.
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sykhan
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(Original post by DFranklin)
Taking logs might make things easier...
plz show me how?? Plz
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sykhan
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Can u solve the question for me plz as its gv me decimal power. And i dont know how to get rid of decimal power to get b.
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Dirac_
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(Original post by sykhan)
When i divide both equation i got b^1.5= 8 now i dont know how to get rid of this decimal power. Plz help me
at GCSE level, you can estimate roots; so you can take the square root of 8 as 2, and because root 2.5 is close to 2 and would give a greater answer, add on around 0.7/0.8 so you get 2.8.

At A-level it's completely different of couce
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thekidwhogames
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Form and solve the system of equations.
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ghostwalker
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(Original post by sykhan)
When i divide both equation i got b^1.5= 8 now i dont know how to get rid of this decimal power. Plz help me
If you square the whole equation you get:

b^{1.5}\times b^{1.5}= 8\times 8

And using the rules for indices we have:

b^3=64

And you've eliminated the decimal part of the power.

Can you finish from there?
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sykhan
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Yes now i did it many thanks😊 so kind of u.
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