Recent content by bcahmel

Thank you LCKurts, vela, and Ray! So to summarize: think of the transformations separately, and then multiply the two transformation matrices together. Thanks again

To dilate:\begin{equation} \left[ \begin{array}{ccc} (12/17) & 0\\ 0 & (12/17) \\ \end{array} \right] \end{equation} To rotate: \begin{equation} \left[ \begin{array}{ccc} cos(3pi/19) & -sin(3pi/19)\\ sin(3pi/19) & cos(3pi/19)\\ \end{array} \right]...

Homework Statement The vector A has length 8.5, and makes an angle of 5pi/19 with the x-axis. The vector B has length 6, and makes an angle of 8pi/19 with the x-axis. Find the matrix which rotates and dilates vector into vector . Homework Equations Rotation matrix in...

I get what you're saying, but I really need to know how to solve it with algebra...

Homework Statement determine the intervals on which the function is concave up or down and find the points of inflection. f(x)= x-lnx for x>0 The Attempt at a Solution f '(x)=1 -(1/x) f"(x)= 1/x^2 I know to find concavity and inflection points you take the second derivative and...

ok, thank you so much! You really helped! The answer should have been obvious I guess- since sin and cos both have max and min of 1 and -1 anyway for their range.

I guess for the min I got -1 and the max I had 1. Is this right?

so sin(pi+0.7297) =3.8712??

So... cosx=0 at pi/2, 3pi/2 sinx=0 at 0, pi, 2pi sinx=-2/3 at -0.7297, ahh I forget trig,how do you get the second value?

yes, I get it now...thanks mark44

Homework Statement Find the min and max of sin^3(x) - cos^2(x) on the interval [0,2pi] The Attempt at a Solution So I took the derivative, which is 3sin^2(x)cos(x) + 2cos(x)sin(x) Then I set it to 0 and factored to get the crit pts: 0=(cosxsinx)(3sinx+2) so cosx=0, sinx=0, and...

ok, so its just like y=mx+b, sort of..

thanks lanedance, I typed it wrong on the computer- but you're right that is the derivative. And vela, that's makes sense. So I think I did the error part right!

Homework Statement stimate Δf using the Linear Approximation and use a calculator to compute both the error and the percentage error. f(x) =1/(1+x^2) , a = 3, Δx = 0.5 Homework Equations f'(a)(x) percentage error= abs(error) divided by actual value The Attempt at a Solution So...

Homework Statement If the price of a bus pass from Albuquerque to Los Alamos is set at x dollars, a bus company takes in a monthly revenue of R(x) = 1.5x − 0.01x2 (in thousands of dollars). Suppose that x = 80. How will revenue be affected by a small increase in price? Explain using the...