An equation expresses the relation between variables. A relation between y and x can be drawn as a graph in the xy plane.
In order to do that, you want to "plug in" a value for x, and then get the result as a value for y. With an equation that expresses y in terms of x, you can do just that. For example, plug in the value x=3 in the equation y=2x+4 easily gives you y=10. You plot the point (3,10) and repeat for different x.
If y is not clearly expressed in terms of x, you get equations like: 2x + 4y + x/y = 0. You cannot plug in an x and calculate a y in an easy way.
Most of the time you'll be able to rewrite the equation in the right "pluggable" form. In fact, when you have an equation in this form, it maps one to one to a function f(x). y=2x+4 and f(x)=2x+4 is kind of the same thing. "f is a function of x" and "y is expressed in terms of x" are similar statements.
Answer:
It's wrong
Step-by-step explanation:
TO determine the mass of the helium in the balloon, we make use of the density of the gas that is given in the problem and the volume of helium that is present. <span>Density is a property of a
material which describes the mass of a material per unit volume. By multiplying the volume to density, we get the mass of the helium gas in the balloon. We do as follows:
Mass = Density x Volume
Mass = 0.1785 kg / m^3 x 3249 m^3
Mass = 579.9465 kg
Therefore, the mass of helium gas in the hot air balloon would be about 579.9 kg.</span>
If you represent the problem in a diagram, you will form a triangle with 3 known length of the sides. When you are given all sides, and you are asked to find an angle, you can use the cosine law.
b^2 = a^2 + c^2 - 2ac*cosB
1.4^2 = 1.9^2 + 1^2 - 2(1.9*1)(cosB)
B = 45.78°
