# ISI2015-DCG-27

1 vote
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If $A$ be the set of triangles in a plane and $R^{+}$ be the set of all positive real numbers,  then the function $f\::\:A\rightarrow R^{+},$ defined by $f(x)=$ area of triangle  $x,$ is

1. one-one and into
2. one-one and onto
3. many-one and onto
4. many-one and into

retagged

1 vote Hence, option$(C)$ is the correct answer.

0

@`JEET how do you know that area of triangles in the plane will cover all the positive real numbers.

i.e Do you have a proof that Range = R+

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