• We need your support!

    We are currently struggling to cover the operational costs of Xtremepapers, as a result we might have to shut this website down. Please donate if we have helped you and help make a difference in other students' lives!
    Click here to Donate Now (View Announcement)

Mathematics: Post your doubts here!

Messages
3,225
Reaction score
15,036
Points
523

Thought blocker

XPRS Moderator
Messages
8,526
Reaction score
34,855
Points
718

Thought blocker

XPRS Moderator
Messages
8,526
Reaction score
34,855
Points
718
GCE As and a level
4i)
(x/k)+k = x^2/4
=>4((x/k)+k) = x^2
=>4x/k=x^2-4k
=>4x = kx^2 - 4k^2
=>kx^2-4x-4k^2 = 0
Use b^2 - 4ac = 0
16 +16k^3 = 0
k = -1 :)

4ii)
kx^2-4x-4k^2 = 0 put k as -1 and get your x value as -2
now as we have y = x^(2)/4 put 2 as x, you get y as 1
so P is (-2,1) :)

6ii)
from part i) you got 2sin^(2)x + 3sinx -2 = 0
By solving this quadratic eqn, you get 2 values of sin theta i.e is 0.5 and -2 well sin inverse is not defined at -2 so consider sin theta to be 0.5 ; Now, sin inverse 0.5 is 30. Here we have 2y instead of x so for one value of y it will be 30/2 = 15 and for 2nd value of y will be (180-30)/ 2 = 75 . :)

7ii)
For AB to be unit vector it should equal to 1
hence,
(k-1)^2 + K^2 + (2k - 2)^2 = 1
6k^2 -10k + 4 = 0
now you got k as 1 or 0.67

8i)
Use ar^(n-1) formula here,
so for second term , ar^(2-1) = 24 and for fourth term, ar^(4-1) = 13.5
Now equate each other and get r as 3/4 and first term (a) as 32 :)

8ii)
use a/(1-r) formula, you get answer as 128 :)

8b)
ZaqZainab Suchal Riaz Idk this one ask 'em.


10ii)
When d2y/dx^2 is > 0 it has minimum value. Here it is > 0 i.e is minimum point :)


11)
Suchal Riaz ZaqZainab

Actually I am tired of typing. :/ Help him now, I have to do organic chemistry :/
 
Top