Prove, using the second derivative, that the general quadratic y = ax^2+bx+c, is:

a) always convex when a>0

b) always concave when a <0

Planes have edges true or false

Which of the following statements is false: if a number is a natural number, the it is rational If a number is a whole number, then it is rational If a number is fraction, then it's rational If a number is an interger, then it's irrational

Verify the identity cos (x + pi/2) = - sin x

Mr. Driscoll has 9 reports to grade there are 6 pages for each report he graded 12 pages how many pages does he still have to grade?

Jane & David 81 quarts of berries at kings orchard if David picked 6 more than twice the number of quarts Jane picked how many quarts did Jane pick?

What is the maximum value of P = 24x + 30y, given the constraints on x and y listed below? x+y (less than or equal to) 5 x-y (greater than or equal to) - 1 x (greater than or equal to) 0 y (greater than or equal to) 0 120 132 138 150

The theater is sold 1456 tickets at the theater sold six times as many regular price tickets as it's all discount tickets

Maritza remembers her pin because it is the product of two consecutive prime numbers that is between 1000 and 1500 what is her pin

The triangle and the trapezoid have the same area. Base b (two) is twice the length of base b (one). What are the lengths of the bases of the trapezoid? Triangle: - b=21 cm & h=6cm. Trapezoid:-h=6cm

Which is equivalent to 10 to the 4? 10 * 10 * 10 * 10 4 * 4 * 4 * 4 * 4 * 4 * 4 * 4 * 4 * 4 10 * 4 (10 * 4) * (10 * 4) * (10 * 4) * (10 * 4)