Recent content by Macleef

  1. M

    Find Extreme Values for f(x) Equations

    Could you find the extreme values for the following equation if there isn't any restrictions? For example, Could you find the absolute max and min for this equation? f(x) = -x^{4} + 4x^{3} Or do you need the restrictions: f(x) = x^2 + 16x^{-1} , 1 \leq x \leq 4
  2. M

    Limits - Did I do the questions correctly?

    I thought instantaneous value means the same thing as slope and slope means the same thing as finding the derivative? My teacher wanted the class to use those formulas mentioned and yes it was a typo..it's y' = (b^x)(lnb)
  3. M

    Limits - Did I do the questions correctly?

    Homework Statement If you invest $5000 in a stock that is increasing in value at the rate of 12% per year, then the value of your stock is given by: f(x) = 5000(1.12)^x, where x is measured in years a) find average value from x = 2 to x = 3 b) find instantaneous value at x = 3...
  4. M

    Law of Vectors (Cross Product)

    Homework Statement Prove: (au) × v + (bu) × v = [(a + b)u] × v Homework Equations http://en.wikipedia.org/wiki/Cross_product The Attempt at a Solution u = ( x , y , z ) v = ( x₂, y₂,z₂) LHS: = (au) × v + (bu) × v = [ ay z₂- y₂az , - (axz₂- x₂az) , axy₂- x₂ay ] + [ by z₂- y₂bz , - (bxz₂-...
  5. M

    Proving Identity: |a × b|² + (a•b)² = |a|²|b|²

    Homework Statement The identity below is significant because it relates 3 different kinds of products: a cross product and a dot product of 2 vectors on the left side, and the product of 2 real numbers on the right side. Prove the identity below. | a × b |² + (a • b)² = |a|²|b|²...
  6. M

    Vectors: Collinear Demo - P,Q,R & D,E,F

    I don't follow. . . The question does mention what are x1, x2, y1, y2, (if relevant) z1 and z2. . . And from my attempted solution, I did find the vectors. . .but I don't know what to do after finding the vectors. . .
  7. M

    Vectors: Collinear Demo - P,Q,R & D,E,F

    Homework Statement Using vectors, demonstrate that these points are collinear. a) P(15 , 10) , Q(6 , 4) , R(-12 , -8) b) D(33, -5, 20) , E(6, 4, -16) , F(9, 3, -12) Homework Equations \frac{x_{1}}{x_{2}} = \frac{y_{1}}{y_{2}}...
  8. M

    Finding Equilibrium: Solving a Force Problem

    Homework Statement A box with a weight of 215 N rests on a ramp. There is a frictional force of 27 N exerted on the box directed up the ramp. If the ramp is inclined at 30 degrees, what force must be applied at an angle of 40 degrees to the ramp to maintain equilibrium? Textbook Answer...
  9. M

    Applications of Dot Product: Finding Force Components on an Inclined Plane

    What? I don't understand what you meant by "in FBD= W points down and your points up in +ve y"
  10. M

    Applications of Dot Product: Finding Force Components on an Inclined Plane

    Homework Statement 15) In Question 14, if the ramp makes an angle of 20 degrees with the level ground. Find the magnitude of the force tending to lift the crate vertically. Textbook Answer for Question 15: 108.3 N ---- 14) A crate is being dragged up a ramp by a 125 N force applies at an...
  11. M

    Geometric Vectors Homework: River, Motor Boat, Marina

    Homework Statement A river is 2 km wide and flows at 6 km/h. A motor boat that has a speed of 20 km/h in still water heads out from one bank perpendicular to the current. A marina lies directly across the river on the opposite bank. Use Geometric Vectors to solve this problem. a. How far...
  12. M

    How Do You Calculate Resultant Forces Using Geometric Vectors?

    Then how would you graph the problem? I don't understand the wording. . .
  13. M

    How Do You Calculate Resultant Forces Using Geometric Vectors?

    I tried doing sine law, but I keep getting error. And the angles you've provided don't give the right resultant. The only angles that do give me approximately 9.8 N are 118, 119 and 120 degrees. But, I want to know how to solve this problem without looking at the answers because my test is...
Back
Top