Discussion about math, puzzles, games and fun. Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ • π ƒ -¹ ² ³ °
You are not logged in.
Post a reply
Topic review (newest first)
If you look inside the brackets of the numerator the sum within them is raised to the one-half power which is the same thing as taking the square root but just different notation.
I've been using the quadratic formula to solve equations on which I first complete the square. I notice you are using the same formula here but without the sqrt?
Wow thanks, I'll make my answer a little more specific next time.
I would personally use the quadratic equation for this problem:
I know the answer was right, I looked it up
Factorising -x² + 4x + 5 gives you (x+1)(5-x), so the roots would be -1 and 5.
I'm given the function f(x)=-(x-2)^2+9 and asked for the maximum value (9) and to sketch the graph of y=f(x) showing where the curve crosses the axis. I'm not sure of the standard way to work backwards but I worked back to y = -x^2 + 4x + 5 and tried to factorise it to get the points where it crosses the x-axis.