Saturday

October 22, 2016
Total # Posts: 36,333

**Incorrect Subject label - Maths**

discussed here: http://www.jiskha.com/display.cgi?id=1412345782

*August 5, 2016*

**ALGEBRA**

this has been answered

*August 5, 2016*

**A**

Once you see the pattern, listing 7 numbers in each case is a trivial problem. Option 1 - they tell you the pattern Option 2 - square the numbers Option 3 - double the previous number

*August 5, 2016*

**Math**

6 workers do 1 km in 4 days 1 worker does 1 k m in 4/6 or 2/3 days 4 workers do 1 km in 8/3 days 4 workers do 3 km in 3(8/3) or 8 days

*August 4, 2016*

**insight academy**

amount invested at 10% -- x amount invested at 12% ---- 12000 - x .10x + .12(12000 - x) = 1280 easy to solve for x

*August 4, 2016*

**Math**

you probably meant: A= (x+4)/(xsquared+9x+20) = (x+4)/((x+4)(x+5)) = 1/(x+5) , x ≠ -4 B = (3xsquared-9x)/(xsquared+3x-18) = 3x(x - 3)/((x+6)(x-3)) = 3x/(x+6) , x ≠ 3 clearly they are not equivalent I am sure you can handle the algebra from this point.

*August 3, 2016*

**math**

value = mt + 1500 when t = 4, value = 800 800 = 4m + 1500 4m = -700 m = -175 value = -175t + 1500 plug in t = 5 to find value

*August 3, 2016*

**someone please help me. - Precalc**

y=cos(x−5π/2) amplitude = 1 period = 2π If we had the simple curve y = cos x the quarter points would be (0,1) , (π/2, 0) , (π, -1), (3π/2 , 0) , and repeating at (2π, 1) but we shifted our basic cosine curve 5π/2 units to the right, so...

*August 3, 2016*

**Math**

It says f'(x) = 2x-1 for x ≤ 1, so x = 1 is included and valid for f'(x) to get f'(1) = 1 for x ≤ 1, f(x) = x^2 - x + c which is a parabola opening upwards, we don't know c but notice that when x = 1 , f(1) = c so it "ends" at (1,c) for x&...

*August 3, 2016*

**Math**

height --- 4.9 base --- 3.9 area = (1/2)base x height = ...

*August 3, 2016*

**Math Problem**

lots of "dogs and chicken" problems listed below in Related Questions. Take a look at some of them

*August 3, 2016*

**Math**

Think about where the zeros can come from 1! = 1 , 2! = 2 , 3! = 6 , 4! = 24, 5! = 120 <-- our first zero ..... 10! = 3628800 <-- our 2nd zero that is, a zero comes from a number ending in 2 multiplied by a number ending in 5, or by a number ending in 0 so the zeros ...

*August 3, 2016*

**maths**

cost price ---- x final selling price = 1.04x but that represents 90% of the marked price so the marked price = 1.04x/.9 = 1.1555...x so the marked price is 15.55..% higher than the cost price. e.g. suppose the cost price is $100 marked up price = 100(1.155...) = 115.56 now ...

*August 3, 2016*

**math**

suppose you had 5 bags and each bag would contain 6 apples. How many apples would you have? What operation did you just perform? Do the same for your question.

*August 3, 2016*

**calculus**

height = -4.9t^2 + vt+ c but it said "groundlevel" ---> c=0 height = -4.9t^2 + vt 0 = -4.9(400) + 20v 20v = 1960 v = 98 So the initial velocity was 98 m/s height = -4.9t^2 + 98t d(height)/dt = -9.8t + 98 = 0 at maximum height -9.8t + 98 = 0 t = 10 seconds (We ...

*August 2, 2016*

**Math**

routine right-triangle trig. cos35° = 42/hypotenuse hypotenuse = 42cos35 = 34.4 ft to the nearest whole number, 34 ft

*August 2, 2016*

**math**

It gets even more complicated when you consider that more than likely compound interest would have been used. So at what rate are 24 payments equivalent to a present value of 3438 ? 165(1 - (1+x)^-24)/x = 3438, where x is the monthly rate tough to solve, used Wolfram: http://...

*August 2, 2016*

**maths**

number of boys ---- b number of girls ----- g b = 4g + 3 b-3 = 4g g= (b-3)/4 e.g. let the number of boys be 43 then girls = (43-3)/4 = 10 4 times the number of girls plus 3 = 4(10)+3 = 43 which is the number of boys

*August 2, 2016*

**Math**

They would be separating at 500 ft/min time to go 3000 ft at that speed = 3000/500 min or = 6 minutes or time taken --- x minutes distance of one student = 300x distance of other student = 200x 300x + 200x = 3000 500x = 3000 x = 6 , just like above.

*August 2, 2016*

**Math**

1 L take you 64/7 km 9/8 L take you (64/7) * (9/8) or 72/7 km or 10 2/7 km = appr 10.29 km again, I repeat my concern about decimals vs fractions. First of all you rounded off intermediate answers, so the error just gets compounded

*August 2, 2016*

**Math**

40 5/6 = 240/6 + 5/6 = 245/6 review how to change a mixed fraction to a usable fraction.

*August 2, 2016*

**Math**

(5/9) / x = (245/6) / 1 245x/6 = 5/9 245x = 6(5/9) = 10/3 x = 10/735 = 2/147 or appr .0136 1 cm^3 weighs 2/147 kg you are correct, notice that since the original data was given in exact fractions, it might be a good idea to state the answer as a fraction

*August 2, 2016*

**Opt math**

Let ABC be a right-angled triangle with ∠ABC = 60° and ∠CAB = 30°. Let ABD be a right-angled triangle on the same side of AB with ∠ABD = 40° and ∠DAB = 50° Suppose that AC and BD intersect at E, and that the length of BC is 1, so that ...

*August 2, 2016*

**Math**

25x³-36x step1, common factor = x(25x^2 - 36) step2, recognize the difference of squares = x(5x-6)(5x+6)

*August 2, 2016*

**maths**

original price ---- x reduced price = .8x number of kg purchased at original price = 160/x number of kg purchased at reduced price = 160/(.8x) 160/(.8x) - 160/x = 2/5 200/x - 160/x = 2.5 40/x = 2.5 2.5x = 40 x = 16 find the original rate ???? the reduced price = .8(16) = 12.8...

*August 2, 2016*

**maths**

I sure hope these are not US or Canadian dollars. number of kg of expensive : cheaper = 5x : 2x cost = 250(5x) + 75(2x) = 1400x selling price = 230(7x) = 1610x percent gain/loss based on cost price = (1610x - 1400x)/(1400x) = 210/1400 = .15 profit is 15%

*August 2, 2016*

**math**

If the question had the dimensions are whole numbers. How about x = appr 1.98 ? http://www.wolframalpha.com/input/?i=2(x(2x)+%2B+x(x%2B2)+%2B+2x(x%2B2))+%3D+63

*August 2, 2016*

**Math**

number of ducks ---- d number of goats ----- g d + g = 30 , they have 1 head each 2d + 4g = 94 or d + 2g = 47 subtract the two equations: g = 17 the d + 17 = 30 ----> d = 13 state the conclusion

*August 2, 2016*

**maths**

What is 1 - (.8)(.9) as a percentage ?

*August 2, 2016*

**maths**

find the original rate ? you meant: find the original price ? let original price be x .8x = 160 x = 160/.8 = 200 but that is for 2.5 kg so original price per kg = 200/2.5 = 80 reduced price per kg = 160/2.5 = 64 notice that 64 equals 80% of 80

*August 2, 2016*

**Math 6th Grade**

the LCM ≥ GCF So the only cases to get a product of 12 is: 12 1 6 2 4 3 suppose we have a LCM of 12 and a GCF of 1 how about 12, 1 coming from 3,4 checking: so the number pair (3,4) has a LCF of 1 , and a HCM of 12, product is (1)(12) = 12 looks good! does 6,2 work? LCM...

*August 2, 2016*

**maths**

total time = 5 hrs, 15 minutes = 5.25 hrs let the total journey be 2x time at 60 km/h = x/60 time at 45 km/h = x/45 x/60 + x/45 = 5.25 = 21/4 times 180 , the LCD 3x + 4x = 945 7x = 945 x = 135 total distance = 2x = 270 km check: 135/60 = 9/4 hrs 135/45 = 3 hrs total time = 9/4...

*August 2, 2016*

**maths**

let the travel time be t hrs let the stoppage time be s hrs without stopping, distance = 60t with stops, distance = 40(t+s) 60t = 40t + 40s 20t = 40s t = 2s So for any given time, the train spends twice the time driving as it does stopping or in hour , the time stopping is 20 ...

*August 2, 2016*

**Math**

brother's age ---- x Lily's age ------- x+ 14 8 years from now: brother's age = x+8 Lily's age = x+14 + 8 = x + 22 x+22 = 2(x+8) solve for x and sub into my definitions

*August 1, 2016*

**Calculus**

find their intersection x^2 - 4x + 1 = -x^2 + 4x - 5 2x^2 - 8x + 6 = 0 x^2 - 4x + 3 = 0 (x-1)(x-3) = 0 x = 1 or x = 3 look at http://www.wolframalpha.com/input/?i=y+%3D+x%5E2+%E2%88%92+4x+%2B+1+,+y+%3D+%E2%88%92x%5E2+%2B+4x+%E2%88%92+5 As you can see, they cross at (1,-2) and...

*August 1, 2016*

**algebra quadratic equations**

base --- x height = x-1 area of triangle = (1/2) base x height (1/2)(x)(x+1) = 105 x^2 + x = 210 x^2 + x - 210 = 0 (x+15)(x-14) = 0 x = -15 or x = 14, but x > 0 base is 14 cm, height is 15 cm check: area = (1/2)(15)(14) = 105 all is good!

*August 1, 2016*

**maths**

after markup ---- > 140% after discount --- .75(140)% = 105% so the trader makes a profit of 5%

*August 1, 2016*

**maths**

right now: number of girls ---- x number of boys --- x+15 after increase: girls ---- 1.15x boys ---- 1.2(x+15) boys - girls = 29 1.2(x+15) - 1.15x = 29 1.2x + 18 - 1.15x = 29 .005x = 11 x = 220 there are 220 girls and 235 boys or a total of 455 students check: 1.2(235) = 282 1...

*August 1, 2016*

**math**

I do not understand the question.

*August 1, 2016*

**Calculus**

Let the right-hand corner vertex be P(x,y) but 3x+2y = 1 y = (1-3x)/2 or 1/2 - (3/2)x area = xy = x(1/2 - (3/2)x) = (1/2)x - (3/2)x^2 d(area)/dx = 1/2 - 3x = 0 for a max of area 3x = 1/2 x = 1/6 y = 1/2 - (3/2)(1/6) = 1/4 ---> P is (1/6 , 1/4) max area = xy = (1/6)(1/4) = 1...

*August 1, 2016*

**PreCalculus**

You didn't define your x and y, but I will assume that they represent length and width. So your first equation of xy = 30 is correct Your second equation makes no sense I will let x be one of the sides costing $55/ft From the data, I get Cost = 40x + 15(x+2y) = 40x + 15x...

*August 1, 2016*

**Math**

13/9 + 10/3 + 4 = 13/9 + 30/9 + 36/9 = ...

*August 1, 2016*

**maths**

The slope of a line equals tan A, where A is the angle that the line makes with the x-axis So the slope of your line is tan (-135°) = 1 then y = x + b but (3,4) lies on it, ... 4 = 3 + b b = 1 y = x + 1 or x - y = -1

*August 1, 2016*

**math (integral)**

You probably meant y=e^(-x^2) look at the graph http://www.wolframalpha.com/input/?i=y%3De%5E(-x%5E2) the maximum ordinate is y = 1 however, the function never reaches the x-axis, so there is a "gap". Unless you left out some vertical boundaries, the question is bogus.

*July 31, 2016*

**math (integral)**

Did you mean y = ln x ? , I will assume you did Make a sketch to see the region in question. so you want ∫ lnx dx from x = 1 to e = [xlnx - x] from 1 to e = elne - e - (1ln1 - 1) = e - e - 0 + 1 = 1 (the integral of lnx should be in your repertoire of standard integrals)

*July 31, 2016*

**Math**

not enough information: Are the chairs in a line? Are the chairs in a circle? Suppose they are in a line. Number of ways to choose 5 of the 8 chairs to seat the boys = C(8,5) = 56 but for each of those choices, we can arrange the 5 boys in 5! ways. number of ways to seat 5 ...

*July 31, 2016*

**maths**

We could do it algebraically but there are so few choices, let's just take the cases. "its unit's digit exceeds twice its ten's digit by 2" ---> 14, 26, 38, 4x, the x would have to be 10 so 14, 26, or 38 in which of these do we get a product of 24 from...

*July 31, 2016*

**algebra**

x^2 + x^2/(x+1)^2 = 3 times (x+1)^2 x^2(x+1)^2 + x^2 = 3(x+1)^2 x^2(x^2 + 2x + 1) + x^2 = 3(x^2 + 2x + 1) x^4 + 2x^3 + x^2 + x^2 = 3x^2 + 6x + 3 x^4 + 2x^3 - x^2 - 6x - 3 = 0 nasty equation, so I tried Wolfram, http://www.wolframalpha.com/input/?i=x%5E4+%2B+2x%5E3+-+x%5E2+-+6x...

*July 31, 2016*

**kaushik**

Simple interest or compound interest? at simple interest, let the original be $x change our times to months ---> 2 yrs, 3 months = 27 months interest = x(.11)(27/24) = 99x/800 x+99x/800 = 4491 x(1 + 99/800)= 4491 x = 3996.44 in 3 years: amount = 3996.44 + 3996.44(.11)(3) = ...

*July 31, 2016*

**math**

assuming log2 (4y) means log2 (4y) I could write 5 as log2 32 so we have: 5 - log2 (4y) = log2 32 - log2 (4y) = log2 (32/(4y)) = log2 (8/y)

*July 30, 2016*

**pre algebra**

let the smaller be x let the larger be 44+x translate: "Five times the smaller is equal to 8 more than the larger" ----> 5x = 44+x + 8 4x = 52 x = 52/4 = 13 smaller is 13 , larger is 57 check 57-13 = 44 , check!! 5 times the smaller is 65 is 65 greater than 57 by ...

*July 30, 2016*

**math**

one number .... x other numbr .... 2x + 3 x(2x+3) = 35 2x^2 + 3x - 35 = 0 it factors .... (2x-7)(x+5) = 0 x = 7/2 or x = -5 but since the numbers are negative x = -5 one number is -5 the other is -7

*July 30, 2016*

**Calculus AB**

From you subject title, I will assume you have studied vectors. let r be the resultant vector 40 min at 3.5 mph = 7/3 miles 20 min -----> 7/6 miles 60 min -----> 7/2 miles 15 min -----> 7/8 miles r = ((7/3)cos0, (7/3)sin0) + ((7/6)cos245, (7/6)sin245) + ((7/2)cos345...

*July 30, 2016*

**Calculus AB**

So the other angle must be 180-2(55) or 70° draw in the height, h You now have a right-angled triangle, let the hypotenuse be x you can find the height by tan 55° = h/10 you can find the side by cos 55° = 10/x once you have x, you can find the perimeter. once you ...

*July 30, 2016*

**Calculus AB**

That was my answer.

*July 30, 2016*

**Calculus AB**

If you make a good sketch , this is not that hard I labeled the cars as A for the farther none, and B as the closer one. Let C be the base of the building So we want to find AB Two right-angled triangles, were clearly the angle at A is 29.5° and the angle at B is 38.2°...

*July 30, 2016*

**Calculus AB**

Let's visualize what we have here: recall that cos Ø = adjacent/hypotenuse and arccos((x+1)/2) mean we have an angle Ø so that cos Ø = (x+1)/2 so construct a right-angled triangle with base of x+1 and hypotenuse 2 and base angle of Ø Let the ...

*July 30, 2016*

**Math**

4*15-11+8-2 = 55

*July 30, 2016*

**Maths**

just plug in n = 1, n = 3, n = 5 If will do the n = 3 S(n) = 3(3) - 2 = 7

*July 30, 2016*

**Math**

Probably meant to type: x= 2-3t, y= -1+5t from x= 2-3t, -----> t = (2-x)/3 rom y= -1+5t ---> t = (y+1)/5 (2-x)/3 = (y+1)/5 3y+3 = 10 - 5x 5x + 3y = 7 slope = -5/3

*July 30, 2016*

**Math**

What is a "po" ?? are we solving 4(4x)^2 + 2(4x) + 5 = 0 ?? (we "solve" equations, you had no equation) let 4x = y, so your equation becomes 4y^2 + 2y + 5 = 0 y = (-2 ± √-76)/8 = (-2 ± 2√19 i)/8 = (-1 ± √19 i)/4 4x...

*July 29, 2016*

**MATH**

the way you typed it ... a = -(1)^n 1^anything = 1 so a = -1

*July 29, 2016*

**math**

a=2/3b 3a = 2b b = 3a/2 c=3/2b 2c = 3b b = 2c/3 thus: 2c/3 = 3a/2 4c = 9a 4/9 = a/c a : c = 4 : 9 notice 2/3b ≠ 2/(3b) I assumed you meant it the way you typed it.

*July 29, 2016*

**statistics**

it said "without replacement" , so the prob that the second is faulty is not 15% Bernie, what part of my solution did you not like ? http://www.jiskha.com/display.cgi?id=1469831346

*July 29, 2016*

**math**

There are actually more than what I gave you. Mine are only from the addition of these angles. How about subtractions ? e.g. 45 - 30 = 15 Can you find some more?

*July 29, 2016*

**math**

How would you get 145°

*July 29, 2016*

**math**

mmmh??? I could do a 30°, 45°, 60° , 90° , 75°, 105°, 120°, 135°, 150°, 165° Can you see any I missed ?

*July 29, 2016*

**Maths**

My assumption is that this question contains a typo. The effect is that I can't do the question.

*July 29, 2016*

**math**

complementary angles add up to 90° let the two angles be 3x and 2x, then their difference is x but 3x + 2x = 90 5x = 90 x = 18 the difference in the two angles is 18° check: one is 3(18) = 54 the other is 2(18) = 36 and what is their difference ??

*July 29, 2016*

**Math**

width ---- w length ---- w+5 P = 2w + 2(w+5) = 2w + 2w + 10 = 4w + 10 4w + 10 ≤ 150 4w ≤ 140 w ≤ 35 max width is 35 m

*July 29, 2016*

**Math**

I am a bit confused myself, unless you have a typo. I will assume you meant your first set to be x = 3-2t, y = -2 + 5t so -1+ 3s = 3 - 2t ---> 2t + 3s = 4 ** and -2 + 5t = 5 - 9s ---> 5t + 9s = 7 *** 3 times ** ---> 6t + 9s = 12 subtract *** t = 5 back in ** 10 + 3s...

*July 29, 2016*

**statistics**

done, look back

*July 29, 2016*

**statistics**

prob = (3/20)(2/19) = 3/190 same question as: I have 20 marbles of which 3 are red I choose 2 without replacement, what is the probability that they are both red

*July 29, 2016*

**math**

So we need a triangle with area of 30 cm^2 let the length of each of the equal sides of the isosceles triangle be x, and the height be h h^2 + 6^2 = x^2 ** but we also know that the area of the triangle is (1/2)(12)h = 30 6h = 30 h = 5 then in ** 25 + 36 = x^2 x^2 = 61 x = &#...

*July 29, 2016*

**math**

By the definition of a rhombus , all sides are equal, so if one side is 10, then all sides are equal to 10. Also, the diagonals bisect each other at right angles creating 4 congruent right-angled triangles. Looking at one of these triangles, we have sides 3x, 4x, and ...

*July 29, 2016*

**oops - Calculus**

dont' know where the 65 came from simply change it to 64 and complete the solution, you should get 48 and 16

*July 28, 2016*

**Calculus**

A product is the result of a multiplication. "product of one of them plus the cube of the other" is mathematically confusing, since "plus" implies addition. I will assume you meant: "product of one of them with the cube of the other" let the one ...

*July 28, 2016*

**maths**

(3-√-16) = 3 - 2i recall: √-1 = i √-16 = √4 x √-1 = 2i

*July 27, 2016*

**Math**

let the two numbers be x and x+1 x + x+1 = S 2x = S - 1 x = (S-1)/2 The square of the larger number minus the square of the smaller number = (x+1)^2 - x^2 = x^2 + 2x + 1 - x^2 = 2x + 1 = (S-1) + 1 = S check: let's take 37, and 38 sum = 75 square of larger =1444 square of ...

*July 27, 2016*

**Math**

15/4 = 3.75 or = 3 3/4 as a mixed fraction or how about (1/2)(7.5) or (1/4)(15 or .....

*July 27, 2016*

**GP**

so the GP terms are: a+d, a+3d, and a+6d (a+3d)/(a+d) = (a+6d)/(a+3d) (a+6d)(a+d) = (a+3d)^2 a^2 + 7ad + 6d^2 = a^2 + 6ad + 9d^2 ad = 3d^2 divide by d a = 3d common ratio : r = (a+3d)/(a+d) = 6d/(4d) = 3/2

*July 27, 2016*

**Maths**

Did you look at http://www.jiskha.com/display.cgi?id=1469612090

*July 27, 2016*

**Maths**

after 1 day, the two clocks will show a difference of 5 minutes after 2 days, the two clocks will show a difference of 10 minutes ... after n days the clocks will show a difference of 5n minutes. One day consists of 1440 minutes. number of days needed to make up this time = ...

*July 27, 2016*

**maths**

Since you gave the dimension of only one wall, let's assume that the room is square. As Steve showed in his calculation, one wall has an area of 5x3 or 15 m^2 So 4 walls have an area of 60 m^2 if 6 litres cover 10 m^2 1 L will cover 10/6 or 5/3 m^2 number of litres of ...

*July 27, 2016*

**Algebra**

time of Bell's sprinklers --- x hrs time of Patterson's ------- 65-x hrs solve for x: 15x + 25(65-x) = 1225

*July 26, 2016*

**geometry**

well, it could either be 8, 8, 10 or 8, 10, 10 so which fits?

*July 26, 2016*

**MAth Trig**

72° = (π/180)(72) radians = 2π/5 radians arc = rØ 32 = 2π/5 r r = 80/π so the diameter is 160/π cm or appr 50.9 cm or 72/360 = 32/(2πr) 144πx = 32(360) x = 80/π , as above

*July 26, 2016*

**Maths**

The two scales where they coincide are -40 degrees in both units There are many places in the world where such temperatures exist. In my Canada these are the top 10 lowest temperatures recorded. http://www.durhamregion.com/whatson-story/5153897-top-10-coldest-temperatures-...

*July 26, 2016*

**Math**

Abegail --- x years Alger ---- x-7 years x(x-7) = 144 x^2 - 7x - 144 = 0 (x - 16)(x + 9) = 0 x = 16 or x = -9, the last does not make sense. sub back in my definitions

*July 26, 2016*

**Army school math**

let each of the equal sides be x 2x + 6 = 26 x = 10 make a sketch of the triangle, draw in its height h h^2 + 3^2 = 10^2 h = √91 area = (1/2)(6)√91 = 3√91 cm^2 which is the same as DrBob's answer

*July 26, 2016*

**Trigo**

I made a sketch, showing two right-angled triangles. One is : base angle 28°, height = 30 tan28 = 30/base base = 30/tan28 other triangle: let the distance between ships be x tan23° = 30/(base + x) base + x = 30/tan23 x = 30/tan23 - base = 30/tan23 - 30/tan28 = 14.25 m

*July 26, 2016*

**physics**

first leg: a = 1 v = t + c when t = 0 , v = 0 , thus c = 0 v = t s = (1/2)t^2 so after 20 seconds, s = (1/2)(400) = 200 m v = 20 m/s (or 72 km/h ) second leg: at constant speed, no acceleration v = 20 m/s s = rate x time = 20(1800) = 36000 m last leg: a = ? v = at + 20 when t...

*July 26, 2016*

**Math**

size of side of square to be cut out --- x cm volume = (25-2x)(32-2x)(x) = 1575 expanding we get: 4x^3-114x^2 + 800x = 1575 4x^3 - 114x^2 + 800x - 1575 = 0 messy to solve, gave up trying to factor, and used Wolfram: http://www.wolframalpha.com/input/?i=solve+4x%5E3+-+114x%5E2...

*July 25, 2016*

**CHECK MY ALGEBRA 2**

Scott was right, the denominator causing the vertical asymptote at x = -2 is x+2 final answer: f(x) = (x-4)/( (x-4)(x+2) )

*July 25, 2016*

**pre cal**

You should know that we can only take logs of positive numbers, so x-1 > 0 x > 1 so the vertical asymptote is x = 1

*July 25, 2016*

**Math**

the the circle be x^2 + y^2 = r^2 then y = √(r^2 - x^2) or (r^2 - x^2)^(1/2) let the length of the rectangle be 2x, and the height be 2y then the vertex in quadrant I is (x, (r^2 - x^2)^(1/2) ) area = 2x(2y) = 4xy = 4x((r^2 - x^2)^(1/2)), remember r is a constant d(area...

*July 25, 2016*

**Please help me solve this - PreCalc**

let x = π/6 for easier typying so your 1/cos2 * π/16 - 1/cot2 * π/16 = 1/cos^2 x - 1/cot^2 x = sec^2 x - tan^2 x since sec^2 x = 1 + tan^2 x , = 1 + tan^2 x - tan^2 x = 1

*July 25, 2016*

**pre cal**

plug in your values, assuming you meant f(x) =a (2)^(bx) and not what you typed. for (0,3) , 3 = a(2)^0 --> 3 = a for (1,4) , 4 = 3(2)^b 2^b = 4/3 take logs of both sides, and use log rules b log2 = log4 - log3 b = (log4 - log3)/log2 = appr .415037

*July 25, 2016*

**math**

smaller number --- x larger number ---- x+5 "the sum of two numbers is 25" translate into an equation and solve.

*July 23, 2016*

**Maths**

Use your definitions: a + ar^2 = 7/3 a( 1 + r^2) = 7/3 ** ar + ar^3 = 7/4 a(r + r^3) = 7/4 *** divide *** by ** (r + r^3)/(1 + r^2) = (7/4) / (7/3) = 3/4 4r + 4r^3 = 3 + 3r^2 4r^3 - 3r^2 + 4r - 3 = 0 r^2(4r - 3) + 1(4r-3) = 0 (4r-3)(r^2 + 1) = 0 4r = 3 or r^2 = -1 , the last ...

*July 23, 2016*