4、编写程序,用牛顿切线法求方程f(x)＝ 5x^3+2x^2-12x-16＝0（其 中^表示幂运算）在区间[1,2]上

#include
#include
void main()
{
void function1();//搜索法
void function2();//二分法
void function4();//牛顿法
int choice;
printf("请选择求解的方法:nt1.搜索法nt2.二分法nt3.牛顿法n:");
switch(1)
{
case 1:function1();
case 2:function2();
case 4:function4();
}
}
void function1()//搜索法计算非线性方程的解
{
double expression1(double);
double lpoint=1.0,rpoint=2.0,step=0.0001;
while(expression1(lpoint)0.00001)
{
mpoint=(lpoint+rpoint)/2;
if(expression1(lpoint)*expression1(mpoint)0.00001)
{
x=x-expression1(x)/expression2(x);
}
printf("运用牛顿法所求结果:%fn",x);
}
double expression1(double x)
{
double result;
result=x*x*x-x*x-1;
return result;
}
double expression2(double x)
{
double result;
result=3*x*x-2*x;
return result;