Advertisements
Advertisements
Question
Make f the subject of the formula D = `sqrt((("f" + "p")/("f" - "p"))`. Find f, when D = 13 and P = 21.
Advertisements
Solution
D = `sqrt((("f" + "p")/("f" - "p"))`
squaring both sides, we get
⇒ D2 = `(("f" + "p")/("f" - "p"))`
⇒ D2(f - p) = (f + p)
⇒ D2f - D2p = f + p
⇒ D2f - f = p + D2p
⇒ f(D2 - 1) = p(D2 + 1)
⇒ f = `("p"("D"^2 + 1))/(("D"^2 - 1)`
Substituting the values of D = 13 and p = 21
f = `(21(13^&2 + 1))/((13^2 - 1)`
= `(21 xx 170)/(168)`
= 21.25.
APPEARS IN
RELATED QUESTIONS
The simple interest on a sum of money is the product of the sum of money, the number of years and the rate percentage. Write the formula to find the simple interest on Rs A for T years at R% per annum.
The fahrenheit temperature, F is 32 more than nine -fifths of the centigrade temperature C. Express this relation by a formula.
How many minutes are there in x hours, y minutes and z seconds.
Make a the subject of formula x = `sqrt(("a" + "b")/("a" - "b")`
Make V the subject of formula K = `(1)/(2)"MV"^2`
Make d the subject of formula S = `"n"/(2){2"a" + ("n" - 1)"d"}`
If V = pr2h and S = 2pr2 + 2prh, then express V in terms of S, p and r.
Make a the subject of the formula S = `"n"/(2){2"a" + ("n" - 1)"d"}`. Find a when S = 50, n = 10 and d = 2.
Make I the subject of the following M = `"L" /"F"(1/2"N" - "C") xx "I"`. Find I, If M = 44, L = 20, F = 15, N = 50 and C = 13.
Make c the subject of the formula a = b(1 + ct). Find c, when a = 1100, b = 100 and t = 4.
