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Mathematics: Post your doubts here!

izzahzainab

izzahzainab

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VampGirl said:
Need help in p1 O/N/06 q:10 (iii) (iv) (v) and M/J/07 q:11 (ii) (iv)
Click to expand...
Q10)
c) The answer to part two is f(x)= (x - 1.5)^2 - 2.25
we know that it will be graphed as a parabola that opens upwards (because x has a positive coefficient).
So we need too find the minimum value of f(x) ie -2.25. You can visualize that all the values of f(x) are greater than or equal to -2.25 since it is the minimum point of the curve.

iv) Since the graph is a parabola, every "y" value has 2 corresponding x values, ie the graph is not a 1:1 function. Only 1:1 functions have an inverse so this graph doesn't.

v) let 'radical x' be represented by z.
so x = z^2
z^2 - 3z - 10 = 0
solve the quadratic equation and you'll get z=-2 and z= 5
replace z with 'radical x'. Since anything squared is always positive, -2 is discarded. Now 'radical x' equals 5. square both sides. Final answer: x= 25
 
Rutzaba

Rutzaba

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izzahzainab said:
Q10)
c) The answer to part two is f(x)= (x - 1.5)^2 - 2.25
we know that it will be graphed as a parabola that opens upwards (because x has a positive coefficient).
So we need too find the minimum value of f(x) ie -2.25. You can visualize that all the values of f(x) are greater than or equal to -2.25 since it is the minimum point of the curve.

iv) Since the graph is a parabola, every "y" value has 2 corresponding x values, ie the graph is not a 1:1 function. Only 1:1 functions have an inverse so this graph doesn't.

v) let 'radical x' be represented by z.
so x = z^2
z^2 - 3z - 10 = 0
solve the quadratic equation and you'll get z=-2 and z= 5
replace z with 'radical x'. Since anything squared is always positive, -2 is discarded. Now 'radical x' equals 5. square both sides. Final answer: x= 25
Click to expand...
and izzah saved the day!!!! :D

ps. i love ur name
 
VampGirl

VampGirl

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izzahzainab said:
Q10)
c) The answer to part two is f(x)= (x - 1.5)^2 - 2.25
we know that it will be graphed as a parabola that opens upwards (because x has a positive coefficient).
So we need too find the minimum value of f(x) ie -2.25. You can visualize that all the values of f(x) are greater than or equal to -2.25 since it is the minimum point of the curve.

iv) Since the graph is a parabola, every "y" value has 2 corresponding x values, ie the graph is not a 1:1 function. Only 1:1 functions have an inverse so this graph doesn't.

v) let 'radical x' be represented by z.
so x = z^2
z^2 - 3z - 10 = 0
solve the quadratic equation and you'll get z=-2 and z= 5
replace z with 'radical x'. Since anything squared is always positive, -2 is discarded. Now 'radical x' equals 5. square both sides. Final answer: x= 25
Click to expand...
Thank u :)
Nd cn u plz help me with q11 as well :)
 
Rutzaba

Rutzaba

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Rutzaba

Rutzaba

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Rutzaba said:
Yar frst u take lcm of this equation

That will give you xb + ay = ab

Then at p where on x axis y = 0 if u put that value of y into abv equ ul get that a=x

then at Q y axis x wud be zero... put that into eq abv ul get y=b

P (a,0) and Q ( 0, b)
Click to expand...
then ul get 1 equation by putting it in the distance formula... and the othr equation by putting it in the gradient formula...

solve two eqs simultaneously and ud get the answer insha Allah :)
 
Binyamine

Binyamine

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Yousif Mukkhtar said:
Got a question guys, please help:
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_s11_qp_13.pdf
Q3)
Click to expand...

Rutzaba showed you the way.

( x / a ) + ( y / b ) = 1
Use the first information; to find P and Q.

On x-axis, y=0

x = a. Hence Coordinate P ( a , 0 )

On y-axis, x = 0

y = b. Hence Coordinate Q ( 0, b)

Next nformation; Length PQ is (45^ (1/2) )

manipulating the data;

a^ 2 + b ^ 2 = 45..............................First Equation

Next Information; Gradient = -1/2

b / (-a) = -1/2
a = 2b .............................................Second Equation

Solving the First and Second Equation Simultaneously would yield the following answer

b = 3 ; a = 6
 
Rutzaba

Rutzaba

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Binyamine said:
Rutzaba showed you the way.

( x / a ) + ( y / b ) = 1
Use the first information; to find P and Q.

On x-axis, y=0

x = a. Hence Coordinate P ( a , 0 )

On y-axis, x = 0

y = b. Hence Coordinate Q ( 0, b)

Next nformation; Length PQ is (45^ (1/2) )

manipulating the data;

a^ 2 + b ^ 2 = 45..............................First Equation

Next Information; Gradient = -1/2

b / (-a) = -1/2
a = 2b .............................................Second Equation

Solving the First and Second Equation Simultaneously would yield the following answer

b = 3 ; a = 6
Click to expand...
may i be darned if i eva get that neat and clean ! :p
 
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