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Two dice and the difference of squares |
2009-04-21 |
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From dave:
I dont understand how to do this: Two fair dice are rolled. What is the probability that the difference of the squares of the numbers is divisible by three? the answer is 5/9
Answered by Harley Weston. |
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The derivative using limits |
2009-04-21 |
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From Kirstin:
I am trying to take the limit of f(x) = [f(x+h)-f(x)] / h
If you try taking the limit by substituting the limiting value h=0, you get 0/0,
which of course is not the right answer. You rewrite f(x+h)-f(x) so it has a factor
of h in it, which you cancel with the h in the denominator before you substitute h=0.
But I am not sure how to do this. Thanks.
Answered by Robert Dawson. |
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A max-min problem |
2009-04-20 |
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From Charlene:
A fixed circle lies in the plane. A triangle is drawn
inside the circle with all three vertices on the circle and two of the vertices at the
ends of a diameter. Where should the third vertex lie to maximize the perimeter
of the triangle?
Answered by Penny Nom. |
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The shadow of a tree |
2009-04-20 |
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From Lindsey:
James found that a 30 ft. tree that cast a shadow of 40 ft. A wire from the top of the tree to the beginning of its shadow must be how long?
Answered by Penny Nom. |
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The interior angles of a pentagon |
2009-04-20 |
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From Mary:
If four interior angles of a five-sided figure pentagon measure 100 degrees each, what will the fifth angle measure?
Answered by Harley Weston. |
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12 oz. cup |
2009-04-19 |
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From Tom:
I am a ceramic teacher and wanted my students to make a 12 oz. cup, what formula should we use?
Answered by Chris Fisher. |
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Factor x squared(x-3)+(x-3) |
2009-04-19 |
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From Victor:
How do I factor x squared(x-3)+(x-3) ?
Answered by Harley Weston. |
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cos2x = sinx |
2009-04-19 |
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From stacey:
solve the equation cos2x = sinx for 0 < x < 2 pi
giving the answer in terms of pi.
Answered by Harley Weston. |
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Two similar rectangles |
2009-04-19 |
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From Alyssa:
The ratio of the lengths of corresponding sides of two similar rectangles is 3:5. the small rectangle has an area of 36 square centimeters. What is the are of the large rectangle?
Answered by Penny Nom. |
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28 golfers |
2009-04-18 |
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From DON:
HI, I HAVE 28 GOLFERS AND I NEED A SCHEDULE FOR 24 DIFFERENT DAYS
THERE WILL BE 7 GROUPS OF 4 PLAYERS EACH DAY. ALL PLAYERS WOULD LIKE TO PLAY WITH ONE
ANOTHER AS EVEN AS POSSIBLE (SAY 2 TO 4 TIMES EACH OVER THE 24 DAYS)...THANKS DON
Answered by Victoria West. |
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Four-digit combinations |
2009-04-18 |
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From Carri:
How many 4-digit combinations can be made out of digits 1, 2, 3, 4, & 5 using each number once? What are the combinations?
Answered by Penny Nom. |
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The height of a right triangle |
2009-04-17 |
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From drakkar:
how do i find the height of a right triangle that in 176 feet in area
Answered by Penny Nom. |
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Nickles and dimes |
2009-04-17 |
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From Emily:
a vending machine contains nickels and dime coins which totals an amount of $14.50. There are 95 more nickels than the number of dime coins. How many of each coin does exist?
Answered by Penny Nom. |
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A geometry problem |
2009-04-17 |
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From Yueh:
Let ABC be a triangle. Locate the point O inside the triangle ABC such that for points L, M and N lying on its sides AB, BC, and CA respectively, triangles BOL, COM, and AON have the same area, where LO and BC, OM and AC, NO and AB must be parallel respectively.
Answered by Chris Fisher. |
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Make x the subject in this equation |
2009-04-16 |
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From victoria:
hi,
i need help trying to make x the subject in this equation:
7y + 2x = 15
i'm really stuck so any help will be good,
thanks
Answered by Penny Nom. |
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