ElectricPavlov

Sub into the equation

6 = 15 sin (2pi 120 t)

6/15 = sin(240 pi t)

.4115 R = 240 pi t

.4115 R = pi t

t = .131    sec

x = value of furniture sold

.07   is   7% in decimal

.07 * x = 240

x = 240 / .07 = 3428.57 dollars worth of furniture

21.5 hours  *  11.60 / hour   = 249.40 dollars

Which is it    245 dollars    or  240 dollars ?

10000 possible codes

21 xx   would lead to only 100 codes       100 out of 10000     1/100

(-1, -2 )     via the quadratic formula (assigning each half of the left side = 2)

Three out of the eight figures are triangles      so    3/ 8

Vertex form   ( vertex is at -1,-1)

y =a (x+1)^2 - 1      find a convenient integer point (not the vertex) on the graph to calculate the value of 'a'  (0,0 is a good one)

0 = a (1) -1            so a = 1

y = (x+1) ^2 -1      expand to get the requested form

y = x^2 + 2x +1 - 1

y = x^2 + 2x + 0       take it from here ....

via Google :

The SI unit of specific heat capacity is joule per kelvin per kilogram, J⋅kg−1⋅K−1. For example, the heat required to raise the temperature of 1 kg of water by 1 K is 4184 joules so the specific heat capacity of water is 4184 J⋅kg−1⋅K−1.

or, in calories:

The specific heat of water is 1 calorie/gram °C = 4.186 joule/gram °C

How far above the floor ?