bloody c4 help

i have been stuck on this question for 2 days please someone out their help me out of my misery. part c

3b. binomial expansion of (1+1.5)^0.5= 1+0.75x-9/32x^2

3c. hence show that ((2+3x)/8)^0.5 approx.= a +bx+cx^2

Reply 1

Petronella

Would love to help but hard to read question written like that anyway you can go online and copy the question?

Reply 2

jameswhughes

Original post by whizz-kid

It needs factorising and then you will get the second part, like this; (x/8)^0.5=(x/2)^0.5(1/4)^0.5=(1/2)(x/2)^0.5.

Reply 3

whizz-kid

Original post by jameswhughes

It needs factorising and then you will get the second part, like this; (x/8)^0.5=(x/2)^0.5(1/4)^0.5=(1/2)(x/2)^0.5.

i dont understand in the markscheme it says: 0.5+(3/8)x + (9/64)^2

(edited 13 years ago)

Reply 4

jameswhughes

Original post by whizz-kid

i dont understand in the markscheme it says: 0.5+(3/8)x + (9/64)^0.5

Yeah, that's right. What I was trying to say is when you take the quarter out it comes out as a half, because of the square root, so the new answer is half of what you had for the first answer.

Reply 5

whizz-kid

Original post by jameswhughes

Yeah, that's right. What I was trying to say is when you take the quarter out it comes out as a half, because of the square root, so the new answer is half of what you had for the first answer.