ACT Prep Exam 55 Questions with Verified Answers 2021
Circumference of a circle - CORRECT ANSWER 2πr
Area of a triangle - CORRECT ANSWER A=(base x
... [Show More] height)/2
Area of a trapezoid - CORRECT ANSWER A=(base 1 + base 2)/2 x height
phythagorean theorem - CORRECT ANSWER a^2 + b^2 = c^2
area of a circle - CORRECT ANSWER A=πr²
Volume of a cylinder - CORRECT ANSWER V=πr²h
sector - CORRECT ANSWER fraction of area of circle
x/aπ = 45/360
x/aπ = 1/8
8x = aπ
x=a/8 π
arc - CORRECT ANSWER fraction of circumference
x/aπ = 45/360
x/aπ = 1/8
8x = aπ
x = 3/4 π
area of a parallelogram - CORRECT ANSWER A=bh
Volume of a sphere - CORRECT ANSWER 4/3πr³
equation of a circle - CORRECT ANSWER (x-h)²+(y-k)²=r²
(h,k) = center
radians to degrees - CORRECT ANSWER multiply by 180/π
eg: 3π/2 x 180/π=270 degrees
degrees to radians - CORRECT ANSWER multiply by π/180
270 x π/180=3π/2
sin - CORRECT ANSWER sine= opposite/hypotenuse
cos - CORRECT ANSWER cos=adjacent/hypotenuse
tan - CORRECT ANSWER tan=opposite/adjacent
unit circle - CORRECT ANSWER a circle with a radius of 1 = to hypotenuse
difference of cubes - CORRECT ANSWER x³ - y³ = (x - y)(x² + xy + y²)
sum of cubes - CORRECT ANSWER x³ + y³ = (x + y)(x² - xy + y²)
difference of squares - CORRECT ANSWER x² - y² = (x + y)(x - y)
a^2 + bx + c - CORRECT ANSWER take the factors of a & c that add up to b.
perfect square trinomial - CORRECT ANSWER a trinomial that is the result of squaring a binomial
a^2 + 2ab +b^2 = (a+b)^2
quadratic equation in standard form - CORRECT ANSWER ax^2+bx+c=0
X^m x X^n - CORRECT ANSWER = X^m+n
X^m/Y^n - CORRECT ANSWER = X^m-n
(X^m)^n - CORRECT ANSWER = X^mn
(XY)^m - CORRECT ANSWER = X^m x Y^m
(X/Y)^m - CORRECT ANSWER = X^m/Y^m
X^0 - CORRECT ANSWER = 1
X^-m - CORRECT ANSWER = 1/X^m
(X/Y)^-m - CORRECT ANSWER = (Y/X)^m
A/X^-m - CORRECT ANSWER ax^m
Distance Formula - CORRECT ANSWER d = √[( X2 - x₁)² + (Y2 - y₁)²]
midpoint formula - CORRECT ANSWER (XI+x₂)/2, (YI+y₂)/2
slope formula - CORRECT ANSWER (Y2-y1) / (X2-x1)
linear equation - CORRECT ANSWER y=mx+b
point slope formula - CORRECT ANSWER y-y1 = m(x-x1)
ellipse (vertical major axis) - CORRECT ANSWER (x-h)^2/b^2 + (y-k)^2/a^2 = 1
*larger denominator is always a^2
ellipse (horizontal major axis) - CORRECT ANSWER x^2/a^2 + y^2/b^2 = 1
*larger denominator is always a^2
parabola standard form - CORRECT ANSWER y=ax^2+bx+c
hyperbola (vertical) - CORRECT ANSWER y^2/a^2-x^2/b^2=1
*positive term is always a^2
hyperbola (horizontal) - CORRECT ANSWER x^2/a^2-y^2/b^2=1
*positive term is always a^2
logbB=1 - CORRECT ANSWER logarithmic base is always 1
eg. logx4=1
logb1=0 - CORRECT ANSWER logarithmic base is always 0
eg. log5x=0
n! - CORRECT ANSWER multiply by decreasing positive integers
eg. 5!= 5 x 4 x 3 x 2 x 1= 120
nPr - CORRECT ANSWER n!/(n-r)!
nCr - CORRECT ANSWER n!/r!(n-r)!
complementary angles - CORRECT ANSWER Two angles whose sum is 90 degrees
supplementary angles - CORRECT ANSWER Two angles whose sum is 180 degrees
integer - CORRECT ANSWER All whole numbers (both positive and negative) and zero.
intercepted arc - CORRECT ANSWER arc that is across from the central angle
*is equal to the measure of central angle
inscribed angle - CORRECT ANSWER an angle whose vertex is on the circle and whose sides are chords of the circle
*half of measure of intercepted arc
reciprocal of sin - CORRECT ANSWER cscx = 1/sinx
reciprocal of sec - CORRECT ANSWER secx = 1/cosx
reciprocal of tan - CORRECT ANSWER cotx = 1/tanx [Show Less]