Prelim Maths help please (1 Viewer)

[marcquelle]

Hey guys can you help me out with some questions the ones in green are top priority ( so can you help me with these first) then the blue


a)Factorise Completely 8x^4 – 64x
b)Simplify √48 - √27 +√3
c)If x=2^2 and y=3^4,express 4^6x27^8 in terns of x and y.
d)Solve the quadratic equation x – 8x – 9 = 0 by completing the square. Give your answer in exact form.
e)…. | 3^x for x > 2
f(x)| √4-x^2 for -2≤x≤2
… .∟-(2+x) for x < -2
f)The roots of the quadratic equation 4x^2 + 9x + 5=0
i) α+β
ii) α β
iii) α -1 + β-1
iv) α2β + αβ2
g)Simplify Cos^2 A Tan2 A + Cos^2 A

(can you please show working)

Thank You in advanced
Marcquelle

<!-- / message --><!-- sig --> __________________

 

[bored of sc]

If x=2^2 and y=3^4,express 4^6x27^8 in terns of x and y.

4⁶.27⁸

= (2²)⁶.(3³)⁸
= x⁶.3²⁴
= x⁶.3^4x6
= x⁶.(3⁴)⁶
= x⁶.y⁶
= (xy)⁶

 

[vds700]

Hey guys can you help me out with some questions the ones in green are top priority ( so can you help me with these first) then the blue


a)Factorise Completely 8x^4 – 64x
b)Simplify √48 - √27 +√3
c)If x=2^2 and y=3^4,express 4^6x27^8 in terns of x and y.
d)Solve the quadratic equation x – 8x – 9 = 0 by completing the square. Give your answer in exact form.
e)…. | 3^x for x > 2
f(x)| √4-x^2 for -2≤x≤2
… .∟-(2+x) for x < -2
f)The roots of the quadratic equation 4x^2 + 9x + 5=0
i) α+β
ii) α β
iii) α -1 + β-1
iv) α2β + αβ2
g)Simplify Cos^2 A Tan2 A + Cos^2 A

(can you please show working)

Thank You in advanced
Marcquelle

<!-- / message --><!-- sig --> __________________

b)√48 - √27 +√3
=4√3 -3√3 + √3
=2√3

f) (i) α+β = -b/a = -9/4
(ii)α β = c/a = 5/4

(iii)α -1 + β-1 =α + β -2 = -9/4 -2 = -17/4

iv) α^2β + αβ^2 = α β(α + β) = (5/4)(-9/4) = -45/16

 

[Timothy.Siu]

a)Factorise Completely 8x^4 – 64x
8x(x^3-8)=8x(x-2)(x^2+2x+4)

c)If x=2^2 and y=3^4,express 4^6x27^8 in terns of x and y.

4^6=2^12=x^6
27^8=3^24=y^6
so its x^6 x y^6
d)Solve the quadratic equation x – 8x – 9 = 0 by completing the square. Give your answer in exact form.

x-8x-9+16=16
(x-4)^2-9=16
(x-4)^2=25
x-4=5 or x-4=-5
x=9 or -1

 

[marcquelle]

thanks guys i had my test today i think i went all right

 

[ratcher0071]

g)Simplify Cos^2 A Tan2 A + Cos^2 A
Thank You in advanced
Marcquelle

<!-- / message --><!-- sig --> __________________

I think you mean:
Cos^2 A Tan^2 A + Cos^2 A
=Cos^2 A (Sin^2 A/Cos^2 A) + Cos^2 A
=Sin^2 A + Cos^2 A
=1