My thread of questions

[khalil]

Q) 3)a) please...

[ngRISING]

heres a few brain teasers that i failed

Question 19
The probability of Kimmy getting a maths question correct in a test is 0.24. What is the fewest number of questions the maths teacher should set to ensure that the probability of Kimmy getting at least two questions correct is more than 0.95?
A. 18
B. 17
C. 16
D. 15
E. 14


Question 2
Which of the following is the definition of an odd function?
A. f(-x) = - f(x)
B. f(x) = f(-x)
C. f(x) = xn, where n is odd
D. f(x) = - f(0)
E.  f(x) = -x


Question 14
The remainder when the function f(x) = x5 - 4x4 + 3x3 + 2x + 1 is multiplied by            is:
A.  0
B.  9
C. 24
D. -3
E. -32


Question 15
2000 metres up in the air, a plane is flying horizontally at a constant speed. At a particularly point in time, the angle is 30◦ and decreasing, and the speed of the aeroplane is 450 km/h. How quickly is the angle decreasing at this point?
A. – 0.013 degrees per hour
B. 0.23 degrees per hour
C. -0.23 degrees per hour
D. 0.11 degrees per hour
E. 0.0140 degrees per hour

[TrueTears]

lol is that from the Medtutor exam?

Anyway

Q2. A, the definition of a odd function is that a reflection in the x axis is the same as a reflection in the y axis.

[ngRISING]

lol is that from the Medtutor exam?

Anyway

Q2. A, the definition of a odd function is that a reflection in the x axis is the same as a reflection in the y axis.

yup. i kinda dislike this exam for some reason. maybe i screwed up a lot of the questions LOL .

[TonyHem]

for 19)Probability of success = 0.24
N = unknown
X = at least 2

1 - binomCDF(n,0.24,1) - you can just do trial and error here.
or
1- nc0(0.24)^(0)*(0.76)^n + nc1(0.24)(0.76)^(n-1) > 0.95
1 - (0.76^(n) + n(0.24)(0.76)^(n-1) > 0.95

0.76^(n) + 0.24n(0.76)^(n-1) < 0.05 or <-- this may be easier

I dunno how to actually "solve it" properly :/

[ngRISING]

TSFX.

tech free 09

sketch the graph wit equation f(x) = -(x-4)(x+2)^2(1-x)^5 labelling the coordinates of the axes intercepts.

how the f*** would i sketch that without a calc ?

[Flaming_Arrow]

TSFX.

tech free 09

sketch the graph wit equation f(x) = -(x-4)(x+2)^2(1-x)^5 labelling the coordinates of the axes intercepts.

how the f*** would i sketch that without a calc ?

well its in factor form so just sketch the interceps and sub in random values of x(0,1,-1) etc to sektch it

[TrueTears]

Looking at the highest power of x which is x^8, it is an even power so it will look like the "even" power graphs.

You will have a x axis intercept at x = 4 and x = -2 and one at x = 1

However lets take a look at the furthest to the right x intercept. Since f(x) is "positive" that means it comes down from the positive half of the y axis. So it comes down from the first quadrant going into the fourth.

At , since it's to the power of 5, it will look similar to as if it is to the power of 3. So it looks like a cubic graph.

Then at it just touches the x axis since it's to the power of 2.

[ngRISING]

just a general question

say e^x = x

for my next line do i need to put

loge (e^x) = loge(x)

or can i just put

x = loge(x)

ty

[/0]

you can skip to x = loge(x)

[ngRISING]

sweet. was curious. cause i do all my prac exams on like 2 sheets. like 2 pages per a piece of paper. be good if i could skip a line ^^

[ngRISING]

wait one more

say the q was

0=4cos(pie/x)-2

can i just write

1/2=cos(pie/x) for the next line

methods might actually be fun for me now LOL

[TonyHem]

yeah you can just write 1/2 = cos(pi/x)

edit: no sorry, you can't write pie or pi, you must write

hehe

[ngRISING]

lol nah ima be cool and write pie.  :uglystupid2:

[ngRISING]

finally an exam where i only screwed up 1 Q LOL ^^

heres the question cause i dont understand the theory



part b

u know when it says f(2x) which i misread has 2(f(X))

if it was f(2x) it would be
2cos[2(pie/x)]-1

if it was 2(f(x)) it would be
2[2cos(pie/x)-1]

right. hence it explains my earlier question lol ==' .