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Using the Pythagorean Theorem |
2007-06-18 |
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From cynthia:
Hi,
If I have a question with a right triangle and it asks....
If ABC is say 400 miles. How much shorter will the miles be if I travel
from BC?
I don't exactly remember the question but, I would I solve a problem
similiar to this one?
Answered by Stephen La Rocque. |
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The length of an arc |
2007-06-18 |
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From Lenny:
How do you find out the arc length of a sector 50 degrees wide??
Answered by Stephen La Rocque and Penny Nom. |
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Babylonian geometry |
2007-06-17 |
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From marleen:
The following problem and the solution were found on a Babylonian tablet dating from about 2600BC:
Problem:60 is the Circumference, 2 is the perpendicular, find the chord.
Solution:
Thou double 2 and get 4
Take 4 from 20, thou gettest 16
Square 16, thou gettest 256
Take 256 from 400, thou gettest 144
Whence the square root of 144, 12 is the chord.
Such is the procedure. Modern day mathematicians have reasoned that the Babylonian Mathematician who solved this problem assumed that the value of Pi is 3. By explaining in detail how the Babylonian Mathematician must have solved this problem, justify the reasoning of the modern mathematicians.
Answered by Stephen La Rocque. |
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The Golden gate bridge |
2007-06-17 |
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From Khan:
I am doing a project on parabola and Bridges. I have chosen the Golden gate bridge
as my bridge. Now The suspension cables are shaped like a parabola.
We have to derive an equation for this parabola. We have to assume the vertex is
(0,0). Now I am having troubles writing the equation in standard form.
The information is this
Height of tower above water:
746 ft = 227 m
Height of tower above roadway:
500 ft = 152 m
Length of one side span: 1,125 ft = 343 m
length of suspension span including main span and side spans: 1.2 miles = 6,450 ft
Now my question is this, i KNOW THE standard form for this parabola opening up would
be (x-h)squared = 4a (y-k)
Since h,k are 0,0 the equation will now take the form of xsquared = 4ay
My question is to find the equation I need to know A how do i get this a based on the above
provided info. Thanks for your help and concern.
Answered by Penny Nom. |
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Period of a sum of trig functions |
2007-06-17 |
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From Aakash:
the period of the function f(x)=cos3x+sin4x+tan4x
Answered by Stephen La Rocque. |
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Isoperimetric area comparison |
2007-06-17 |
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From michael:
An equilateral triangle and a regular hexagon have equal perimeters. If the area of the triangle 10, what is the area of the hexagon?
Answered by Stephen La Rocque. |
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An inequality |
2007-06-16 |
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From jerry:
Two real numbers a and b satisfy the equation ab=1.
i) Prove that a^6 + 4b^6 >4
ii) Find out whether the inequality a^6 + 4b^6 >4 holds for all a and b such that ab = 1
Answered by Stephen La Rocque. |
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Solving a literal equation |
2007-06-15 |
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From Allen:
Solve each literal equation for the indicated variable.
D= C-S/n (solve for s)
and
A=1/2h (B+b) (solve for b)
Answered by Penny Nom. |
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Compatible numbers |
2007-06-15 |
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From meryl:
what is a compatible number? ex.6,321/8
Answered by Penny Nom. |
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What is the 100th term? |
2007-06-15 |
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From George:
I have the sequence
50,120,235,406,644
the 1st difference is 70,115,171,238
the 2nd difference is 45,56,67
the 3rd difference is 11,11
i used the a*n^3+b*n^2+c*n+d rule but the a turns out to be a decimal
because 11/6 is 1.833333333 and so i cant find the formula for the 100th term
term.
Answered by Penny Nom. |
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Algebra : 9x + 7 = 5x - 3 |
2007-06-15 |
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From Allen:
I am having a problem solving for x. The problem is:
9x + 7 = 5x - 3
Answered by Stephen La Rocque. |
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Probability and blood type |
2007-06-15 |
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From Jim:
| Blood Type |
Male |
Female |
Total |
| O |
80 |
370 |
450 |
| A |
150 |
250 |
400 |
| B |
50 |
50 |
100 |
| AB |
20 |
30 |
50 |
| Total |
400 |
600 |
1000 |
What is the probability that the person selected is female if the person’s blood type is O?
What is the probability that the person selected has blood type AB if the person is male?
What is the probability that the person selected is a female with blood type O?
Answered by Penny Nom. |
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An 18% reduction |
2007-06-15 |
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From darren:
I have a figure of 627.30 i need to find out what
the original amount was before 18% was taken away to leave the 627.30
Answered by Penny Nom. |
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Drawing a regular hexagon |
2007-06-15 |
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From Brady:
I'm having troubles drawing a regular hexagon. i know that each angle is 120 degrees but when i do that the length aren't perfect...is there a trick or an easier way of doing this task? thnx.
Answered by Walter Whiteley. |
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Simplifying a quartic rational expression using long division |
2007-06-14 |
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From Megan:
x+2/12x^4+17x^3+0x^2+8x-40=
Answered by Stephen La Rocque and Penny Nom. |
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