If f:R→R and g:R→R are defined by f(x)=2x+3 and g(x)=x2+7, then the value of x for which gf(x)=8 are
0,-6
-1,-2
1,-1
0,6
0,2
Explanation for the correct answer:
Given functions f(x)=2x+3andg(x)=x2+7
Finding the value of gf(x)
∴gf(x)=8⇒g(2x+3)=8⇒(2x+3)2+7=8∵g(x)=x2+7⇒(2x+3)2=8-7⇒(2x+3)2=1⇒2x+3=±1Now,2x=-2or2x=-4x=-1orx=-2
Hence, the correct answer is an option (B).
If f:R→R and g:R→ are defined by f(x)=2x+3 and g(x)=x2+7, then the values of x such that g(f(x))=8 are
If f:R→R is defined by f(x)=2x-2x,∀x∈R,where x is the greatest integer not exceeding x, then the range of f is
Chooseanappropriateoptionandfillintheblanks:
Rs10.1=......paise 101/1010