math

posted by .

A diagram shows a straight line graph of In y against x,passing through the point (0,2) and having gradient -3/2 .
The variables x and y are connected by the equation y=pq^x ,where p and q are constants
Find
(i)the value of p and of q ,to one decimal place
(ii)the equation relating x and y

  • math -

    y = pq^x
    lny = lnp + x lnq

    2 = lnp + 0 lnq
    p = e^2

    1/y y' = lnq
    y' = y ln q
    -3/2 = 2 lnq
    lnq = -3/4
    q = e^(-3/4)

    y = e^2 e^(-3x/4)

  • math -

    Can be more specific? still do not understand ...
    The answer for part (ii) should be y=7.4(0.2)^2
    and the values of q is o.2 ..

  • math -

    sorry. Guess I should not have given that last line, but the values for p and q were given...

    p = e^2 = 7.4
    q = e^(-3/2) = 0.2

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. Algebra...

    Write the equation of a vertical line passing through the point (8,-4). Graph x=8 and see if that is what you want. I don't understand?
  2. math

    On a straight line graph, if the line is going this way \ and it goes through 5 on the x axis and 4 on the y axis then what is it's gradient?
  3. Math

    How can I determine a value of gradient from a graph if the line is curved. (not a straight line) This is where Calculus comes in If a graph is a curve, then the gradient (slope) of the curve is the slope of the tangent that you draw …
  4. maths

    find the gradient of the tangent to the parabola y=4x-x^2 at (0,0) hence calculate the size of the angle between the line y=x and this tangent. (as i cant show you the diagram all that it shows is the line going through (0,0) and having …
  5. math

    i have more than one question so if u no any of the answers please tell me 1.) write the point-slope form of the equation of the line with slope -2 passing through the point ( -5, -9). 2.) write the point-slope form of an equation …
  6. Math

    This question concerns the straight line that passes through the points (−1, 3) and (2, −6). Choose the three true statements from the following. Options A The gradient of the line is 3. B The gradient of the line is −3. …
  7. Mathamatics

    This question concerns the straight line that passes through the points (−1, 3) and (2, −6). Choose the three true statements from the following. Options A) The gradient of the line is 3. B) The gradient of the line is …
  8. math

    With regards to question J: The variables x and y are connected by the equation y = x2 - x - 5. Some corresponding values of x and y are given in the table below. x -4 -3 -2 -1 0 1 2 3 4 5 y 15 7 a -3 -5 b -3 1 7 15 (a) Calculate the …
  9. math

    the straight L has gradient 3 and passes through the point A(-6,4). a) find an equation for L in the form y=mx+c b) straight line R has the equation in the form of -7y+x+14=0. Given that R crosses the y-axis at the point B and intersects …
  10. Math

    The variables x and y are related by the equation y=ax/(x-b),where a and b are constants .When y is plotted against y/x ,a straight line is obtained .The line has gradient 3 and y-intercept 2. (i)Find the values of a and b (ii)Find …

More Similar Questions