qn 3d

r=(I+7j-5k)+(lambda)(3i-j-2k)

find the ratio AC:CB

co-ords of A -5,9,-9 B 25,-1,11 C 4,6,-3

I thought I could do (-5+9-9)*(4+6-3):(4+6-3)*(25-1+11) and workout the ratio that way I get 1:7
but mark scheme gets 3:7 how and why


5a, for the last part of the table when x=2 I always get y=0.766 y=4(x^0.5)e^-x

mark scheme gets 1.083


qn 6)find the integral of 2sin3x sin2x dx I tried parts but went wrong some where





Andrew Cropley

Help with any would be appreciated

OK you don't have to help with 6 now igot that one sorted

qn 3d

r=(i+7j-5k)+{\lambda}(3i-j-2k)

?? What does this have to do with anything? Lagrange multipliers?


find the ratio AC:CB

co-ords of A -5,9,-9 B 25,-1,11 C 4,6,-3

i thought i could do (-5+9-9)*(4+6-3):(4+6-3)*(25-1+11) and workout the ratio that way i get 1:7
but mark scheme gets 3:7 how and why

AC=\sqrt{(-5-4)^{2}+(9-6)^{2}+(-9-(-3))^{2}}=3\sqrt{14}

CB=\sqrt{(4-25)^{2}+(6-(-1))^{2}+(-3-11)^{2}}=7\sqrt{14}

\frac{AC}{CB}=\frac{3\sqrt{14}}{7\sqrt{14}}=\frac{ 3}{7}



5a, for the last part of the table What table? when x=2 i always get y=0.766 y=4(x^0.5)e^-x

mark scheme gets 1.083

I don't know what this is, but if you enter x=2 into y, you get y=0.766. Perhaps you have the wrong formula?