a Show which of the following are valid and which are invalid identifiers: Why?

run_1

2run

double

Char

double-trouble

two*four

b. What's wrong with the following function call:

(3 dots means Im not showing all of the program steps)

#include

double find_scale(double x, int n);

.

.

.

int main(void)

{

double num_1, num_3;

int num_2;

.

.

.

num_3 = Find_scale(num_1, num_2);

.

.

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return(0);

}

double find_scale(double x, int n)

{

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.

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return(0);

}