x
2
+
y
=
16
...
.
(
1
)
x + y = 4 (2)
rearrange (2) to y = 4 - x (could do x = 4 - y )
substitute y = 4 - x into (1)
hence:
4
−
⇒
8
and
0
factor and solve : 2x(x - 4 ) = 0
,
substitute these values into y = 4 - x , to find corresponding values of y.
x = 0 : y = 4 - 0 = 4 → (0 , 4)
x = 4 : y = 4 - 4 = 0 → (4 , 0 )
These are the points of intersection with the line x +y = 4 and the circle
Answer link
Объяснение:
#include <iostream>
using namespace std;
int main()
{
int a, b, c, febrary;
bool isValid;
//setlocale(LC_ALL, "Russian");
cout << "Day:";
cin >> a;
cout << "Month:";
cin >> b;
cout << "Year:";
cin >> c;
if (c % 4 == 0)
febrary = 29;
else
febrary = 28;
isValid = true;
if (b < 1 || b > 12)
isValid = false;
if (a < 1 || b > 31)
if (b == 4 || b == 6 || b == 9 || b == 11)
if (b == 2 && a > febrary)
if (isValid)
cout << "yes";
cout << "no";
}
x
2
+
y
2
=
16
...
...
...
...
...
...
.
.
(
1
)
x + y = 4 (2)
rearrange (2) to y = 4 - x (could do x = 4 - y )
substitute y = 4 - x into (1)
hence:
x
2
+
(
4
−
x
)
2
=
16
⇒
x
2
+
16
−
8
x
+
x
2
=
16
and
2
x
2
−
8
x
+
16
−
16
=
0
⇒
2
x
2
−
8
x
=
0
factor and solve : 2x(x - 4 ) = 0
⇒
x
=
0
,
x
=
4
substitute these values into y = 4 - x , to find corresponding values of y.
x = 0 : y = 4 - 0 = 4 → (0 , 4)
x = 4 : y = 4 - 4 = 0 → (4 , 0 )
These are the points of intersection with the line x +y = 4 and the circle
x
2
+
y
2
=
16
Answer link
Объяснение:
#include <iostream>
using namespace std;
int main()
{
int a, b, c, febrary;
bool isValid;
//setlocale(LC_ALL, "Russian");
cout << "Day:";
cin >> a;
cout << "Month:";
cin >> b;
cout << "Year:";
cin >> c;
if (c % 4 == 0)
febrary = 29;
else
febrary = 28;
isValid = true;
if (b < 1 || b > 12)
isValid = false;
if (a < 1 || b > 31)
isValid = false;
if (b == 4 || b == 6 || b == 9 || b == 11)
isValid = false;
if (b == 2 && a > febrary)
isValid = false;
if (isValid)
cout << "yes";
else
cout << "no";
}