Q. 12 A5.0( 2 Votes )

# Let f and g be real functions defined by f (x) = 2x + 1 and g (x) = 4x – 7.

For what real numbers x, f (x) = g (x)?

Answer :

Given: f and g be real functions defined by f(x) = 2x + 1 and g(x) = 4x-7

To find: For what real numbers x, f (x) = g (x)

Explanation: to satisfy the condition f(x) = g(x), the given real functions should be equal

i.e., 2x + 1 = 4x-7

⇒ 7 + 1 = 4x-2x

⇒ 8 = 2x

Or, 2x = 8

⇒ x = 4

Hence for x = 4, f (x) = g (x)

Rate this question :

If , where x ≠ –1 and f{f(x)} = x for x ≠ –1 then find the value of k.

RS Aggarwal - MathematicsLet , then

Mathematics - ExemplarLet and g (x) = x be two functions defined in the domain R^{+}∪ {0}. Find

(fg) (x)

Mathematics - ExemplarExpress the function f : X → R given by f(x) = x^{3} + 1 as set of ordered pairs, where X = {–1, 0, 3, 9, 7}.

Is g = {(1, 1), (2, 3), (3, 5), (4, 7)} a function? Justify. If this is described by the relation, g (x) = αx + β, then what values should be assigned to α and β?

Mathematics - ExemplarLet and g (x) = x be two functions defined in the domain R^{+}∪ {0}. Find

Mathematics - Exemplar

If f (x) = ax + b, where a and b are integers, f (–1) = – 5 and f (3) = 3, then a and b are equal to

Mathematics - ExemplarLet and g (x) = x be two functions defined in the domain R^{+}∪ {0}. Find

(f – g) (x)

Mathematics - Exemplar