Some questions (1 Viewer)

[PhiL]

Can anyone answer any of these questions please, im not sure if they were right or not:
2b. d/dx(inverseCOS(3x^2))
2e (parts i and ii)
and what was the value of x in question 2C.
Thank u

 

[Sweet_Lemon]

x is 5. something~~ can't remeber~~ it's like 144=7x^2

 

[Sweet_Lemon]

Q2b)

-1/square root (1-9x^4) times the derivative 6x

 

[Sweet_Lemon]

2e i) 16C4

ii) P(4 women) = 9C4/16C4

 

[Sweet_Lemon]

if i remembered correctly..tat's wat i got~

 

[PhiL]

x is 5. something~~ can't remeber~~ it's like 144=7x^2

For this question i thought the answer was x=9
cause (7+x)x=12^2
(x+16)(x-9)
therefore x=9???

 

[Sweet_Lemon]

ya....think i did something wrong...coz our teacher said we DONT need to remember the stupid formula!