add test case for negative exponent with integer base

test/test_exponent.c

@@ -60,6 +60,22 @@ void test_DoubleDecimalBase_for_positive_decimal_exponent(void){
     TEST_ASSERT_DOUBLE_WITHIN(0.0001, 1.332474, r3);
 }
 
+void test_DoubleBase_for_negative_decimal_exponent(void){
+    float r1, r2, r3;
+
+    r1 = expIN(-0.125, 3.0);
+    r2 = expIN(-0.5, 2.0);
+    r3 = expIN(-0.12923, 10.0);
+
+    printf("%lf\n",r1);
+    printf("%lf\n",r2);
+    printf("%lf\n",r3);
+
+    TEST_ASSERT_DOUBLE_WITHIN(0.0001, 0.871685, r1);
+    TEST_ASSERT_DOUBLE_WITHIN(0.0001, 0.707106, r2);
+    TEST_ASSERT_DOUBLE_WITHIN(0.0001, 0.742625, r3);
+}
+
 void test_Exponent_with_positive_number(void){
     double r1, r2, r3;