Math Contest -- Over

[Alluminn]

Ok, it's about time we had a quiz for smarts.

Starting tomorrow, I will put one math problem up every day this week.

The first person to PM me with the correct answer will win the 10k for that day.

Hope you guys know your stuff!

Question 1

Explain which step is incorrect, and why. You only have 1 guess on this problem.

Step 1: Let a=b.
Step 2: Then ,
Step 3: ,
Step 4: ,
Step 5: ,
Step 6: and .
Step 7: This can be written as ,
Step 8: and cancelling the from both sides gives 1=2.

Answer 1

Step 8 is the incorrect step. In order to cancel, from both sides, you would need to cancel by division. Since A and B could be any numbers, including 0, you can not cancel them, since you can not divide by zero.
While it is true for some values, it is not true for all numbers. Therefore, the proof is false.

Question 2

Let's try something a bit easier for today.
You have 2 attempts to answer this, and all must be correct.

Answer the questions based on the following equation.

r=5cos3θ

1) What is this type of graph called?
2) How many "petals" are in this graph?

Hint: Use a graphing calculator. You can google to find one online if you don't own one.

Answer 2

1) Rose Curve Graph
2) 3 petals

Question 3

Super easy one today.

A square has a circle inside it, as shown below. The sides of the square measure 6 in. Use this information to answer the following questions.

1) What is the area of the square?
2) What is the area of the shaded part, to the nearest tenth?
Hint: You will need a scientific calculator for this one. You can find one online if you don't own one.

Answer 3

1) 36 Square Inches
2) 7.7 square inches

Crew can answer these two, but members have priority.

Question 4

Solve the system of equations for x, y, and z.

4x-3y+z = -10
2x+y+3z = 0
-x+2y-5z = 17

Answer 4

(1, 4, -2)

Question 5

Use the equation to answer the following questions.

f(x)=3x^4+2x+1

1) Find the derivative.
2) Find the equation of the tangent line at point (1,6).

Answer 5

1) 12x^3 + 2
2) y=14x-8

 

[Pailzor]

Intelligence on teh intarwebz? Dis can't happinz!! gonk gonk gonk  

[Colour Splash]

Yay!  

[lesslife_morekill]

r u trying to get us to do maths homework?  

[Alluminn]

lesslife_morekill

r u trying to get us to do maths homework?

Hell no!
I could do stuff this simple in my sleep

 

[Rinthia]

Question 1

Explain which step is incorrect, and why. You only have 1 guess on this problem.

Step 1: Let a=b.
Step 2: Then ,
Step 3: ,
Step 4: ,
Step 5: ,
Step 6: and .
Step 7: This can be written as ,
Step 8: and cancelling the from both sides gives 1=2.

Step 2 is wrong. A squared plus A squared plus A squared doesn't equal A times B. It equals 3(ab)
Three times (A times B)  

[Alluminn]

Rinthia

Question 1

Explain which step is incorrect, and why. You only have 1 guess on this problem.

Step 1: Let a=b.
Step 2: Then ,
Step 3: ,
Step 4: ,
Step 5: ,
Step 6: and .
Step 7: This can be written as ,
Step 8: and cancelling the from both sides gives 1=2.

Step 2 is wrong. A squared plus A squared plus A squared doesn't equal A times B. It equals 3(ab)
Three times (A times B)

1) You were supposed to PM it to me
2) You're misread it
It says a-squared + a-squared = a-squared + ab

 

[Alluminn]

Simplistic-Tyranny

FYI, mag.

- Not everyone owns a Graphing Calculator
- Not everyone knows Calculus.

Which is why I'm using different levels of math each day.
Yesterday's was just algebra.
Tomorrow will most likely be geometry.
Today I just decided to do Precal

And there are online graphing calculators

 

[_necie123_]

hey  

[Battlestar Anorexia]

4 get this rolleyes  

[Pailzor]

1. Teh graph type ish called "Pokemon".
2. Trick question. Suicune's a Water Pokemon, and has no petals. 3nodding  

[WordWielder]

the answer to the 3rd question is.

1: 36
2: 7.7