math in hl HELP

[slvri]

zeroes of g? never heard of the zeroes of a function b4

[astarmathsandphysics]

Same as the roots

[astarmathsandphysics]

When i get home

[astarmathsandphysics]

let g(x) = log₅|2log₃x|=0
2 log₃x=1 so x=sqrt(3)
Have I got the question right? I can only see one root.

[IGSTUDENT]

Posting my queries:

1.prove that cos^6(x)+ sin^6(x)=1/8(3cos4x+5)

2.Prove that tan5x=(5tanx-10tan^3(x)+tan^5)/(1-10tan^2(x)+5tan^4(x)). By considering the equation tan5x=0, show that tan^2(pi/5)=5-2sqrt5.

For the 2nd question I was able to do the first part but not the second

Thanks

[astarmathsandphysics]

if tan5x=0 x=tan^-10= pi/5
0=(5tanp-10tan^3 p +tan^5 p)=tanp(5 -10tan^2 p+tan^4 p)
hence solve t^2-10t+5=0 where t=tan^2 p and p=pi/5

[cooldude]

wats GP

geometric progression

[IGSTUDENT]

if tan5x=0 x=tan^-10= pi/5
0=(5tanp-10tan^3 p +tan^5 p)=tanp(5 -10tan^2 p+tan^4 p)
hence solve t^2-10t+5=0 where t=tan^2 p and p=pi/5

thanks a lot

[sweet777]

can u please help me solve this matrix question??

Write 5A²-6A=3I in the form AB=I and hence find A^-1 in terms of A and I

please help fasssssssssttttttttttttt!!!!!!!!!!!!!!!!!!!!!!!

[Alpha]

wats GP

Geometric Progression, I guess.

[astarmathsandphysics]

Few mins

[astarmathsandphysics]

Write 5A2-6A=3I in the form AB=I and hence find A-1 in terms of A and I
5A^2-6A+1=4I so (A-I)(5A-!)=4I so A-1= 4I(5A-1)^-1

[IGSTUDENT]

Need help in a few questions:

1)The polynomial p(x) + (ax+b)3 leaves a remainder of -1 when divided by x+1 and a remainder of 27 when divided by x-2.Find the values of the real numbers a and b.

2)Given that the roots of the equation x3-9x2 +bx -216 =0 are consecutive terms in a geometric sequence find the value of b and solve the equation.

[astarmathsandphysics]

1)x+1=0 so x=-1 p(-1)=(-a+b)^3 =-1 so -a+b=-1 (1)
x-2=0 so x=2 p(2)=(2a+b)=3 so 2a+b=3 (2)
(2)-(1) 3a=4 so a=4/3
b=a+1 =7/3

I did the other one already somewhere - I will try to find a link

[astarmathsandphysics]

The orrts are anyway 1,6,36