Maths Assignment- Various Questions (1 Viewer)

[Itike]

Hi, I need help on the following questions in my maths assignment:
1) The elevation to the top of a high rise building at a place X due west of it is 78º and at a place Y due south of X the elevation is 58º. If the distance from X to Y is 200 metres find the height of the building.<O
<O></O>
2) Show that (Sin A)/(Cos A + Sin A) + (Sin A)/(Cos A – Sin A) = Tan2A<O
<O></O>
3) The angle between the lines y=mx and y=x is 30º. Find the exact value of m.<O
<O></O>
4) The point P (x,y) moves on a path such that’s its distance from a point S(3,5) as the same as its perpendicular distance from the line y=-3. Show that the equation of the path P is (x-3)<SUP>2</SUP>=16(y-1)
<O></O>
5) If (x+1) is a factor of the polynomial P(x)= 2x<SUP>4</SUP>-2x<SUP>2</SUP>-a, find the value of a.<O
<O

For Qn 5 I get a=1 but I don’t think that that is right.<O

 

[cl3nta]

Hey

I only did 2,3,5
I didn't look at 1 and didn't spend enough time on 4 to be of much help. Here are the solutions
Q2)
LHS= SinA/(CosA + SinA) + SinA/(CosA - SinA)
=SinA(CosA - SinA) + SinA(CosA + SinA)/(CosA + SinA)(CosA - SinA)
=SinACosA - Sin^2A + SinACosA + Sin^2A/(CosA + SinA)(CosA - SinA)
=2SinACosA/Cos^2A-Sin^2A
=Sin2A/Cos2A
=Tan2A
=RHS

Q3)
exact value of tan30 I think is root3/3 but I can't remember off the top of my head so check this up in one of your textbooks.

Q5)
Using some thm,

P(-1)=0
therefore,
=2(-1)^4 -2(-1)^2-a = 0
=2-2-a=0
hence
-a=0
so a=0

Hope this helps good luck with the assignment

 

[AlvinCY]

I can't draw diagrams online, so I did it on word and made a pdf, enjoy!

http://www.geocities.com/alvin_cy_mak/Ans.pdf

TA!

 

[Itike]

Thanks for the help guys that has been really usefull