PRE-CALC
ALGEBRA
GEOMETRY
CALCULUS
RIDDLES
100
This model is used to find values of sine, cosine, or radians based on certain triangle proportions.
What is the unit circle?
100
Area formula for trapezoid
What is 1/2* (bottom base+top base)*(height)?
100
sin(x) if cos(x) =3/5
4/5
100
the rule where you slap the baby
What is chain rule?
(copyright credit given to feng upon request)
100
When Josh was 8, his brother was half his age. Now that Josh is 14, how old is his brother?
10
200
Law of Sines
what is sin(a)/A = sin(b)/B = sin(c)/C?
200
2x-5x^2+3=1
-2/5, 1
200
The circumference of a circle is 30
. What is its area?
225pi
200
The second derivative of position.
What is acceleration?
200
If it took 6 people 9 hours to build a barn, how long would it take 12 people to build the same barn?
None, because the barn is already built.
300
Given that f(x) = x^3 - x^2 + 2x + 4 and g(x) = 2x^2+(5x*2x) + 7, what is f(x) + g(x)?
x^3+11x^2+2x+11
300
5x−3≤7−3x
5/4
300
antiderivative of ln(x^2)*9x
9(x^2ln(x)-x^2/2)+c
300
What is the next number in the series? 7,645 5,764 4,576
6,457
400
If sinx+cosx=1/5 and0<x<pi, Then tanx=
-4/3
400
equation of a line parallel to x−y−12=0 that passes through (2, -5)?
what is y=x-7?
400
In the triangle ABC sides AB and CB have equal lengths and the measure of angle ABC is equal to 36 degrees. What is the measure of angle BOC where O is the center of the circle?
144
400
A light is on the top of a 12 ft tall pole and a 5ft 6in tall person is walking away from the pole at a rate of 2 ft/sec. At what rate is the tip of the shadow moving away from the pole when the person is 25 ft from the pole?
3.6923
400
A farmer went to a market and bought a wolf, a goat, and a cabbage. On his way home, the farmer came to the bank of a river and rented a boat. But crossing the river by boat, the farmer could carry only himself and a single one of his purchases: the wolf, the goat, or the cabbage. If left unattended together, the wolf would eat the goat, or the goat would eat the cabbage. The farmer’s challenge was to carry himself and his purchases to the far bank of the river, leaving each purchase intact. How did he do it?
Answer: The farmer takes seven trips over—here are his steps:
1. Take the goat over
2. Return
3. Take the wolf or cabbage over
4. Return with the goat
5. Take the cabbage or wolf over
6. Return
7. Take goat over
500
the equation of a circle that has its center at the origin and is tangent to the line with equation 3x-4y=10?
What is x^2+y^2=4?
500
Vertex of concave up parabola that goes through (1,4) and (-1,4).
What is (0,2)?
500
The measure of one interior angle of a regular polygon is 168.75. How many sides does it have?
32
500
We want to construct a cylindrical can with a bottom but no top that will have a volume of 30 cm3. Determine the dimensions of the can that will minimize the amount of material needed to construct the can.
r=2.1216 h=2.1215
500
A woman wants to enter an exclusive club, but she doesn’t know the password. A man walks to the door and the doorman says 12, the man says 6, and is let in. Another man walks up and the doorman says 6, the man says 3, and is let in. Thinking she’s figured it out, she walks up to the door and the doorman says 10, she says 5, and she isn’t let in. What should she have said?
Answer: Three—the code is the number of letters that are in the number the doorman says.