Recent content by Agent_J

What is the value of za/2 for an 80% confidence interval? a. .255. b. 1.28. c. .0398. d. .525. i know the answer is a, but does anyone know how to calculate that :blushing: ?

so how would I start tackling this question :redface: ?

Find the acute angle that is formed by the line y - (sqrt(3)) x + 1 = 0 and the x-axis. better picture here: http://members.rogers.com/agentj/images/math.jpg I am totally lost with this one. It was from my old trigonometry test, but I don't see the relavance of the question to...

f(x) = -2x^2 + 12x + 12 I was able to express it in standard form and find the maximum value, but I can't seem to get the x-intercepts I got -2x^2 + 12x + 12 = 0 -2 (x^2 - 6x + 6) = 0 does that mean I need to use the quadratic formula or did I do something wrong?

Find 2 positive numbers whose sum is 100 and the sum of whose squares is a minimum. Also, find the minimum sum. I'm not sure how to write mine, but I just tested 99^2 + 1^2 = 9802 then I tested 50^2 + 50^2 = 5000, so obviously its 50 and 50. Also, I don't understand "find the minimum sum"...

uh oh, then I must have done something wrong because the answer for the Radius should be just 1 :frown:

oh ya, I forgot to distribute the 2 how would I find the domain ahrkron :redface:

combining functions - just another check :) f(x) = 2/x g(x) = x/x+2 fog = f(g(x)) = f(x/x+2) =2/x/x+2 =2 * x+2/x =2x+2/x [Edit (by ahrkron): no changes; took back my edit (I meant to reply)... the post is now in its original form]

Find the center and radius of the circle 16x^2 + 16y^2 + 8x + 32y + 1 = 0 So first i simplified the equation by taking out the 16 so i got: 16 (x^2 + 1/2x + y^2 + 2y) = -1 16 (x^2 + 1/2x + 1/16) + 16 (y^2 + 2y + 1) = -1 + 1 + 1 16 (x + 1/4)^2 + 16 (y + 1)^2 = 1 Center =...

let x be the "surd"?

Simplify sqrt(11+sqrt72)) + sqrt(11-sqrt(72)) better picture here http://members.rogers.com/agentj/images/math.jpg I don't know where to begin for this one, but apparently my calculator says the answer is 6 :redface:

Simplify (y^-3 - x^-3) / (xy^-1 + x^-1y + 1) better picture of it here http://members.rogers.com/agentj/images/math2.jpg I tried flipping the variables with negative exponents to the numerator and denominator, but then had no idea what to do next :frown: