Maths SL Preparation for 2013 Exam

[alfie.jnr]

Hey Guys!

I pray everyone who is doing their exams this May 2013 does well! Good luck to you all

I just have a couple of Math SL questions that are really bugging me:

1. The equation x^2 − 3x + k^2 = 4 has two distinct real roots. Find the possible values of k .

I kinda got started off but I'm pretty sure I'm wrong.

2. The line L passes through the point (5, − 4, 10) and is parallel to the vector (4 -2 5)
The Line L intersects the x-axis at the Point P. Find the x-coordinate of P.

My first post here so HELLOOO

[lilianna009]

1.Think about when an equation has two solutions!

Edited May 4, 2013 by lilianna009

[nuby]

For number 1, here's my solution. Hopefully I didn't mess up! I tested it using my graphing calculator and it seems to be correct. I'm sorry I couldn't explain how to solve quadratic inequalities, but

.

Remember:

No real roots: discriminant is less than zero.

One root/Two equal roots/One repeated root: discriminant is equal to zero.

Two real roots: discriminant is greater than zero.

Edited May 4, 2013 by nuby

[Egos]

I hope this helps.

Trial Exam P1 Markscheme.pdf

[alfie.jnr]

Thanks Guys ! Hope exams are good so far

[the phantom]

I have a question how to calculate sum of all values in range of series for example:

^₁₁

∑ (3 + 0.2k) with the Ti-84 and by pen and paper?
^k=0

[Rahul]

Try to create a new topic if your question is unrelated to the original one.

Begin at k=0, substitute in, and add:

(3+0.2(0))+(3+0.2(1))+...+(3+0.2(11))

and then evaluate this sum. Remember that ∑ (a(k)+b(k)) = ∑ (a(k))+ ∑ (b(k))

For calculator, it is explained very well here: http://answers.yahoo.com/question/index?qid=20090316164001AAiEZaT . I've copied it below for convenience.

You'd use the seq( and sum( commands to do that.For example, if you wanted to do summation of 2X+2, upper bound: 7, lower bound: 2, you'd write it as follows:sum(seq(2X+2,X,2,7,1))The basic syntax would be:sum(seq(<expression>, <variable (to solve for)>,<lower bound>,<upper bound>,1Now just your values with the ones above.Note:sum( is found in: [2nd][stat](List) > Math > 5:sum(seq( is found in: [2nd][stat](List) > Ops > 5:seq(