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this must be simple !!?!

find y when

2^y= 4*2^0.5

i can do this by logarithms however i would like to know how to do it without using logarithms as it is a C1 question
Original post by Byrney11
find y when

2^y= 4*2^0.5

i can do this by logarithms however i would like to know how to do it without using logarithms as it is a C1 question


Simplify the RHS into one power (remember that 4 = 2^2).
Reply 2
Original post by Byrney11
find y when

2^y= 4*2^0.5

i can do this by logarithms however i would like to know how to do it without using logarithms as it is a C1 question


write it all out in the same bases

2y=2.2.21/22^y = 2.2.2^{1/2} so 2y=25/22^y = 2^{5/2}

so y= 5/25/2

i think thats right, hopefully :biggrin:
Reply 3
cheers for that.....

what happens with this one then

4^x= 8^2-x
Reply 4
Original post by Byrney11
cheers for that.....

what happens with this one then

4^x= 8^2-x


simplify the powers

Unparseable latex formula:

4^x = 2.2^x = 2^x^+^1



Unparseable latex formula:

8^2^-^x = 2.2.2^2^-^x = 2^5^-^x



Then x+1x+1 = 5x 5-x

and solve that liner equation to find x :biggrin:

EDIT: sorry about my latex, first time using it

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