BackCurrent Flow In electric current flow, it is found that the resistance offered by a fixed length of wire of a given material varies inversely as the square of the diameter of the wire. If a wire 0.01 in. in diameter has a resistance of 0.4 ohm, what is the resistance of a wire of the same length and material with diameter 0.03 in., to the nearest ten-thousandth of an ohm?
Write an equation that expresses each relationship. Then solve the equation for y. x varies jointly as y and z and inversely as the square of w.
Solve each equation. See Example 2. (4x+3)/(x+1) + 2/x = 1/(x2+x)
Solve and check each linear equation. 11x - (6x - 5) = 40
Using k as the constant of variation, write a variation equation for each situation. h varies inversely as t.
In Exercises 1–26, solve and check each linear equation. 7x - 5 = 72
Solve each quadratic inequality. Give the solution set in interval notation.. x2+3x-4<0
In Exercises 67–70, find all values of x such that y = 0.
y = 2[3x - (4x - 6)] - 5(x - 6)
Solve the variation problems in Exercises 77–82. The pitch of a musical tone varies inversely as its wavelength. A tone has a pitch of 660 vibrations per second and a wavelength of 1.6 feet. What is the pitch of a tone that has a wavelength of 2.4 feet?
Solve each equation. Then state whether the equation is an identity, a conditional equation, or an inconsistent equation. 2x/3 = 6 - x/4
What is a conditional equation? Give an example.
Find all values of x such that y = 0. y = 1/(5x + 5) - 3/(x + 1) + 7/5
In Exercises 71–78, solve each equation. Then determine whether the equation is an identity, a conditional equation, or an inconsistent equation. 5x + 7 = 2x + 7
In Exercises 67–70, find all values of x such that y = 0.
Solve each equation. Then state whether the equation is an identity, a conditional equation, or an inconsistent equation. 2x-5 = 7