<p>Hey guys! I am taking the ACT next Saturday and I am freaking out. My highest score was a 24 and aiming for a 27. I have English and Reading down; Math and Science...eh...not too much... Anyway, my Math tutor backed out on me at the last minute and I really need some help. My math teacher didn't teach me anything this past year except how to annoy me. Please give me a list of formulas that would more than likely be on the ACT Test. Thanks</p>
<p>I'm in a somewhat similar position to you...I took a diagnostics exam and recieved a 25, aiming for a 30. </p>
<p>Know the distance formula; I've heard you can basically count on a D=rt question on the test.</p>
<p>Area of a Triangle= 1/2bxh</p>
<p>Know how to find an area, radius, diameter, circumfrence of a circle...</p>
<p>Those are a few you should know</p>
<p>Heron's formula is nice to have- also the distance formula in the way that you plug in two points and get the distance. Perhaps a line and point formula, telling you the equation of the perpendicular line through the point and the distance of the line segment between them..</p>
<p>Oh yeah, quadratic equation - thats always/the most essential.</p>
<p>If you've gone through Algebra II, you should be fine. I forget how many functions/logs (if any) there were, but you should also know the equation for graphing a circle: (X-H)^2 + (Y-K)^2 = R^2 where (H, K) = the center and R is the radius.</p>
<p>My Algebra II teacher was lax as well. She too busy planning for the prom to teach us. If you don't mind, help a girl out.</p>
<p>There is ALWAYS a question about the sum of x amount of numbers. </p>
<p>I believe you can use this equation:</p>
<p>S= n/2 [2a + (n-1)d]</p>
<p>S= sum
n= number of terms
a= first term
d= difference of terms</p>
<p>Example.</p>
<p>The sum of the first 5 numbers of 1,3,5,7,9</p>
<p>S= 5/2 [2+(5-1)2] </p>
<p>S= 25 (If you dont believe me, 1+3+5+7+9 = 25</p>
<p>**The questions are usually more difficult for this you could just add them up one by one.</p>
<p>thanx yanksman25!
That's the formula for the sum in an arithmetic sequence!!!
i keep on forgetting the 2a...</p>
<p>Does anyone know if we need to know any other types of sums?</p>
<p>The way I remember the formula for the sum of an arithmetic series is this. It is the number of terms in the sequence times the average of the first and last term.</p>
<p>n = number of terms
d = common difference
a = first term
l = a + d(n-1) = last term</p>
<p>S = n * (a+l)/2 = n(a+a+d(n-1))/2 = n(2a+d(n-1))/2</p>
<p>which is the same as yanksman25's formula.</p>