Wednesday
August 31, 2016

Posts by STEVE

Total # Posts: 42,956

Pre Calculus
you know that sin^2 x + cos^2 x = 1, so when you expand you have sin^2 x + 2 sinx cosx + cos^2 x recall also that sec^2 x = 1 + tan^2 x cos(pi/2-x) = sin(x) So, what do you think?
July 11, 2016

Math
assuming you mean a parabola, recall that x^2 = 4py has axis x=0 directrix at y = -p latus rectum = 4p So, your equation is (x-2)^2 = 4(y-4) see http://www.wolframalpha.com/input/?i=parabola+(x-2)%5E2+%3D+4(y-4)
July 11, 2016

Math
If there are x math problems, then we know that (4/5) x + 3 = 53
July 11, 2016

math
well, we know that the number is between 5500 and 6500 There must be many possibilities: 5579 5588 5597 ... 6497 6488 6497
July 11, 2016

geometry
the exterior angles of an n-gon add up to 360 degrees.
July 11, 2016

Math
I can only think of 2 and 14 which work
July 11, 2016

pre cal
C'mon, this is just Algebra I: f(x) = a(x-41)(x-p)
July 11, 2016

Math
V = k/P So, PV is constant. You want P such that P*160 = 30*240
July 11, 2016

math
clearly the plant grows at 1/2 cm/week So, you have a slope and a point (0,2) ...
July 11, 2016

pre cal
for x not -1 or 1, put it all over a common denominator, and you have 3x^2-2x-3 = 0 I'm sure you can handle that.
July 11, 2016

Math
63 <= 2(w + w+4) <= 95 63 <= 2(2w+4) <= 95 63 <= 4w+8 <= 95 55 <= 4w <= 87 13.75 <= w <= 21.75 so, the maximum width is 21 That makes the max length 25
July 11, 2016

pre cal
or, just factor it: (√x-2)(2√x-1) = 0 √x = 2 or 1/2
July 11, 2016

chemistry
First balance the equation. The product has a ratio of 1:3 for the atoms. So, 2Cl2 + 6Fl2 = 4ClF3 convert to moles of each reactant The one with the lesser no. of moles needed will limit the reaction. Then figure how many moles of product are produced, and go back to grams.
July 11, 2016

MPA
so, did you do some searches? geez, you can do that at least, right?
July 11, 2016

chemistry
so, do you know what reaction yield means?
July 11, 2016

Maths Year 10 Equations
c(x) = 2100/x s(x) = c(x)+8 = 2100/x + 8 extra credit: how much money did he make on the sales?
July 11, 2016

math
surely you can see that T(k) = 20+5k
July 11, 2016

Calculus
well, surely you must in fact have done some work. rather than mumble some excuses, why not show what you did? Then we can analyze it for accuracy and presentability. The critical numbers are where f'(x) = 0 or f'(x) is undefined. So, what does that give you?
July 11, 2016

Calculus
to find the absolute max/min, you need to check for local extrema in the interval. Then check f(x) at the ends of the interval to see whether they qualify as being more max/min. f'(x) = 2/∛(x-2) clearly that is never zero, so there are no internal local extrema. So, ...
July 11, 2016

maths
well, come on. How many pairs of digits are there that add to 9? Also, you know that the first digit is greater, since reversing the digits makes a smaller number.
July 11, 2016

Physics
Recall that the range is r = v^2/g sin(2θ) so, plug in your numbers and solve for θ.
July 10, 2016

math,maths
(x+2)/x >= 1/5 If x>0, x+2 >= x/5 4x/5 >= -2 x >= -5/2 So, x > 0 If x<0, x+2 <= x/5 4x/5 <= -2 x <= -5/2 So, x <= -5/2 So, in interval notation, x is in (-∞,-5/2]U(0,∞)
July 10, 2016

Math
p(x) = 9x - (3x+4700)
July 10, 2016

Math
Draw a Venn diagram. It is clear that 800-(400+240-B&S) = 160+B&S = 200 B&S = 40
July 10, 2016

Math
40min * 1hr/60min * 69mi/hr * 1gal/23mi = 2 gal
July 10, 2016

Assembly language
so, what have you done so far?
July 10, 2016

Maths
Your answer is correct, but where did that 10 come from in the line above it?
July 10, 2016

Pre-Calculus 11
yes -∛54 = ∛-54 Did you try your answer for the other one?? (2/3)^2-5 is negative. so its square root is not real 3-x = √(x^2-5) 9-6x+x^2 = x^2-5 6x = 14 x = 7/3 Let's try 7/3 3 - 7/3 = 2/3 √(49/9-5) = √4/9 = 2/3 Check the graphs at http://www...
July 10, 2016

science
Since KE = 1/2 mv^2, you just plug in your numbers to get the energy in Joules: 1/2 * 70.0 * (1000m/10s)^2
July 10, 2016

science
Set up your balanced equation. How many moles in 11.2g of lime? Use the equation to figure the moles used Convert that to grams
July 10, 2016

physics
As you recall, the range of such a trajectory is v^2/g sin2θ now just plug in your numbetrs and solve for v
July 10, 2016

sarangz
60 km/hr = 16.67 m/s So, the acceleration is -16.67m/s -------------- = -1.67 m/s^2 10s Since F = ma, now you can find F
July 10, 2016

science
Since v = λf just plug in your numbers
July 10, 2016

math
If you assume 360 days per year, the interest per day is just 1/360 of the annual interest. So, you will be charged 500.00 * 0.18/360 * 364
July 10, 2016

Pre-Calculus 11
Been there, done that: http://www.jiskha.com/display.cgi?id=1468110223 b=6
July 9, 2016

Pre-Calculus 11
I assume you want to simplify 5/7 √(3/2) = 5/7 √(6/4) = 5/7 * 1/2 √6 = 5/14 √6
July 9, 2016

Math
you give the function some input. It applies the rule to the given value. It produces a value as an output.
July 9, 2016

Math
1200 + 9000 = 10200 so, what do you think? unless you meant 1209 thousands = 1,209,000
July 9, 2016

Maths
The co- in cosine, cotangent, cosecant means "of the complementary angle." csc(90-θ) = secθ always
July 9, 2016

Maths - Reiny did it right
sorry. I misread the question.
July 9, 2016

Maths
as usual, draw the triangle -- in this case in QI. sinθ = y/r cosθ = x/r
July 9, 2016

weber state university
when an action is to be completed in the future. For example, By noon I will have eaten six doughnuts. By the time you read this post, you will have already figured it out. The FP tense is formed by will + have + past_participle Never mind the distinction between "will&...
July 9, 2016

geometry
most likely a rectangle, if the cuts are made parallel to the sides
July 9, 2016

Trigonometry
No spherical trig here. The balloon problem might have qualified, but it says "level ground." (a) tanθ = 5/4 (b) review your tangent function. If the balloon travels a distance d, then d = 110 tan31°50' - 110 tan19°20'
July 9, 2016

Maths
did this yesterday: http://www.jiskha.com/display.cgi?id=1467998179
July 9, 2016

Math
The line segment touches bot the x- and y-axes at all times. So, the point p is 3 units away from the x-axis, along the line. So, let the line make an angle θ with the x-axis (measured clockwise). Then picture point P as being at the end of a rod of length 7, which slides...
July 9, 2016

math
20-6-5 = 9 P(yellow) = 9/20
July 9, 2016

math
well, 5^2 = 25
July 9, 2016

discrete math
(g◦f) = g(f) = f^2-2 = (2x+1)^2-2 (f◦g) = f(g) = 2g+1 = 2(x^2-2)+1 x=4f/(2f-1) 2xf-x = 4f f(2x-4) = x f = x/(2x-4) So, the range of f is all reals except x=2. The domain is all reals except 2 and 1/2. The domain of f^-1 is the range of f. The range is all reals ...
July 9, 2016

number magic(math)
The length plus the width = 6 so, how many pairs of integers add up to 6? If you are not restricted to integer values, then there is no limit to how many you can draw.
July 9, 2016

math
usually quantities are not negative values, right?
July 9, 2016

algebra
Add: x-2y+3z = 7 -x+y-2z = -4 --------------- -y+z = 3 Add #2 and 4*#3: 4x+5y+z = -1 -4x+4y-8z = -16 ------------------- 9y-7z = -17 Now you know that z = y+3,so 9y-7(y+3) = -17 9y-7y-21 = -17 2y = 4 y = 2 so, z = 5, x = -4
July 9, 2016

Maths
same as always: clear the fractions to get nr = (r+20)(n-10) nr = (r-4)(n+10) nr = nr + 20n - 10r - 200 nr = nr - 4n + 10r - 40 20n-10r = 200 4n-10r = -40 or, 2n-r = 20 2n-5r = -20 So, r = 2n-20 2n-5(2n-20) = -20 2n-10n+100 = -20 -8n = -120 n = 15 so, r = 10 15 students share ...
July 8, 2016

Maths
If each of n students gets r rupees, nr/(n-10) = r+20 nr/(n+10) = r-4 Now just solve for r and n.
July 8, 2016

Math
there is no average cost. The cost of the items does not change. 3s+8c = 29 8s+3c = 15 11s+11c = 44 Multiply by 2/11 and you have 2s+2c = 8
July 8, 2016

Chemistry
convert each to moles. Write the balanced equation. The reagent with the smaller moles used will limit the reaction. So, figure the moles produced, and convert back to grams.
July 8, 2016

Math
well, x is 4, so just substitute 4 for x and evaluate, to get y. y = 2*4+3
July 8, 2016

Maths
3/2 (2a + 2d) = 48 (a)(a+2d) = 252 a = 16-d, so (16-d)(16-d + 2d) = 252 Now just solve for d
July 8, 2016

Algebra
h+2s = 5.40 3h+s = 8.70 Now just solve for h and s.
July 8, 2016

maths
42
July 8, 2016

Science
You need 0.1 moles for 1L of diluted acid. The concentrated acid has 1.15 moles per liter. So, you need 0.1/1.15 = 0.087 liters of the concentrate. or, 87 ml
July 8, 2016

English
how can one letter indicate an order?
July 8, 2016

Science
h/(500*15) = 1/2 Review the properties of a 30-60-90 right triangle.
July 8, 2016

discrete math
Get out your atlas and look them up. (c) Miri is located in Sabah false, since both are cities in Malaysia
July 8, 2016

math
You have y^2 = 4x This is just the standard equation y^2 = 4px with p=1. Check your book or online for properties of parabolas. You can start here if you wish: http://www.wolframalpha.com/input/?i=parabola+y%5E2+%3D+4x
July 8, 2016

Math
use the distributive property 8a+2a = (8+2)a = 10a just as 8 books + 2 books = 10 books $8 + $2 = $10 and so on.
July 8, 2016

Physics
distance is just 5+8 Use the distance formula (Pythagorean Theorem) to figure the displacement.
July 8, 2016

Maths
done http://www.jiskha.com/display.cgi?id=1467924046 You might check your previous posts before wasting everyone's time posting it all over again...
July 8, 2016

Chemistry
well, how many moles of CH4 is 16g? clearly, 4 times that many atoms of H. But, hydrogen comes as H2, not just H, so divide that by 2.
July 8, 2016

math
apparently you have a 5-digit number xxxxx my tens digit is 7 xxx7x My hundreds digit is 4 less than my tens digit xx34x Now just work your way from there, using the facts given.
July 8, 2016

physics
since R varies as L/A, changing L to 2L requires that we also change A to 2A, since L/A = 2L/2A
July 8, 2016

math
84/(4*60) = 84/240 you can reduce that if you want
July 8, 2016

math
R = {(2,3),(2,9),(3,2),(3,4),(4,3),(4,9),(9,2),(9,4)}
July 8, 2016

chem
google is your friend. Type in your question and you can read many explanations of why this is so.
July 8, 2016

VECTOR HELP URGENT
|a × b| = |a| * |b| * sinθ just plug in your numbers!
July 7, 2016

PreCalculus 1
(a) since Coco can be anywhere on the line y=3, you want the closest that the spider can get to that line. Since sin(t) has a minimum value of -1, y(t) has a minimum of 4.5, so Coco can never get closer than 1.5 ft to the spider. (b) The spider's distance is z^2 = x^2+y^2...
July 7, 2016

precalc
(fog) = f(g) = 2g^2-5 = 2(x+4)^2-5 now just expand that out Now just plug in x=3 for (b).
July 7, 2016

precalc
this is very like the others. By this time you should have some idea how to do them. If you get stuck, some back with your work.
July 7, 2016

precalc
yes, it is.
July 7, 2016

Math
v(t) = v - 9.8t v(0.35) = 0, so initial v = 3.43 Her height y = 10 + 3.43t - 4.9t^2 So, solve for t when y=0
July 7, 2016

physics
the horizontal force is 58 cos27° F = ma so, plug in your numbers and solve for a.
July 7, 2016

Algebra
since distance = speed * time if x is the boat's speed and y is the water's speed, we have 4(x+y) = 48 6(x-y) = 48 Hint: 48 = 4*12 = 6*8
July 7, 2016

Algebra
count the tickets: g+s = 215 count the dollars: 10g+6s = 1990 Now crank it out.
July 7, 2016

Geometry
rewrite as y = 2x-3 and you can read off the slope and intercept
July 7, 2016

Pre-Cal
oops sinx = 8/17 so, cosx = 15/17 sin2x = 2 sinx cosx = 2 * 8/17 * 15/17 = 240/289
July 7, 2016

Pre-Cal
sinx = 8/17 so, cosx = 15/7 sin2x = 2 sinx cosx = 2 * 8/7 * 15/7 = 240/49 do the others similarly.
July 7, 2016

Algebra
Huh? It's already written out. That's how I got the equation. Can you not solve the equation? If you find x, that's how many lbs of worms you need. The rest (30-x) is bears.
July 7, 2016

Algebra
If x lbs of worms, then 7x + 3(30-x) = 4.60*30 This is just like the interest problem, which is also a mixture problem.
July 7, 2016

Pre-Cal
recall that tan(x-y) = (tanx-tany)/(1 + tanx tany)
July 7, 2016

Algebra
If $x is at 8%, then .08x + .09(10000-x) = 860
July 7, 2016

Physics - tense
I'm waiting for the answer here... Talk about tension!
July 7, 2016

Maths
Yeah, I noticed that. I can't figure why the closest answer is so far off. To get 12.2 years, r needs to be 9.58%
July 7, 2016

geometry
review your basic trig functions, and from a distance of x feet, 1149/x = tan 89° Now just solve for x.
July 7, 2016

Calculus
recall that the range of an object is R = v^2/g sin2θ so, figure some pairs of value that make that 100 miles. Of course, that formula implies a flat earth, and 100 miles is far enough away that varying gravity and earth's curvature require some modifications.
July 7, 2016

Maths
For n sides, there are n-2 straight angles, or 2(n-2) right angles. So, n=17
July 7, 2016

MATH Function Transformation
If you mean a polynomial such as a(x-p)(x-q)(x-r)... then a is the vertical scale value, so a = 1/2 means the y values are half as big: a compression ratio. stretching and compression are just two ways of looking at a scale factor. Usually a compression means a < 1 and a ...
July 7, 2016

Math
75 min = 1.25 hours, so 15.4mi/1.25hr = 12.32 mi/hr
July 7, 2016

math
that is one way. The other way is to use the Remainder Theorem and evaluate f(1). That is the remainder R.
July 7, 2016

Math Please Help
you just want d(t) > -16 t^3-9t^2+6t > -16 t^3-9t^2+6t + 16 > 0 (t+1)(t-2)(t-8) > 0 Now, using what you know about the general shape of cubics, you know that this one will come up from the lower left, then cross the t-axis at -1,2,8. Since it started out negative, ...
July 7, 2016

math
review your basic trig functions: h/450 = tan 20°
July 7, 2016

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