<p>on the math section, will there be questions about ellipses and hyperbolas?
in other terms, do we have to memorize the equations (such as ellipse EQ has + and hyperbola EQ has -) and how to find the foci and all that crap?</p>
<p>Maybe ....... but REALLY not likely. Unless you want to make a perfect score, you don't have to study. As for the formulas... if you want to, just put it in your calculator memory.</p>
<p>those are rare... circles are much more common... but it couldn't hurt to recognize the equations just in case... but that's about it.... and hyperbolas are easy b/c that is the only one with a minus sign (-) in the equation</p>
<p>they're rare... but know them just in case</p>
<p>oh ok thx guys</p>
<p>yeah, circles only</p>
<p>with a 1/100 chance of the other stuff being on the test, but don't worry, the test is curved appropriately</p>
<p>Could someone explain more of about the circles? .<em>. sorry I suck at math X</em>x.</p>
<p>x^2 + y^2 = r^2 (radius squared) is the equation for a circle</p>
<p>as with all equations, if there is a minus or plus sign within the x or y term, the graph is shifted accordingly</p>
<p>(x - 2)^2 + (y + 3)^2 = 16 ---- in this equation, the radius is 4 (b/c of radius squared... 4^2)... there is a minus 2 in the x term.... so the graph is shifted right 2 units... there is a plus 3 in the y term, so the graph is shifted down 3 units (remember, you go opposite what you would think when the addition or subtraction signs are inside the parentheses... plus means go left or go down... minus means go right or go up)****... so the circle in this equation is centered at the point (2, -3) and has a radius of 4... make sense?</p>
<p>****this is because in the base equation, it is (x - #)^2 + (y - #)^2 = r^2..... so if the sign still remains -, then the # has to be positive... if the sign changes to +, then the # has to be negative</p>
<p>another topic that i've been seeing a little more on the ACT recently is arc length problems</p>