# lv_nanovg_math.h (/api/draw/nanovg/lv_nanovg_math_h)
Functions [#functions]
nvg_math_is_zero [#nvg_math_is_zero]
Check if the floating point number is zero
```c title=" " lineNumbers=1
static bool nvg_math_is_zero(float a)
```
Parameters
| Name | Type | Description |
| ---- | ------- | ------------------- |
| `a` | `float` | the number to check |
**Returns:** — true if the number is zero, false otherwise
nvg_math_is_equal [#nvg_math_is_equal]
Check if two floating point numbers are equal
```c title=" " lineNumbers=1
static bool nvg_math_is_equal(float a, float b)
```
Parameters
| Name | Type | Description |
| ---- | ------- | ----------------- |
| `a` | `float` | the first number |
| `b` | `float` | the second number |
**Returns:** — true if the numbers are equal, false otherwise
nvg_math_inv_sqrtf [#nvg_math_inv_sqrtf]
Calculate the inverse square root (1/sqrt(x))
```c title=" " lineNumbers=1
static float nvg_math_inv_sqrtf(float number)
```
Parameters
| Name | Type | Description |
| -------- | ------- | ---------------- |
| `number` | `float` | the input number |
**Returns:** `float` — the inverse square root
Macros [#macros]
NVG_MATH_PI [#nvg_math_pi]
```c title=" " lineNumbers=1
#define NVG_MATH_PI 3.14159265358979323846f
```
NVG_MATH_HALF_PI [#nvg_math_half_pi]
```c title=" " lineNumbers=1
#define NVG_MATH_HALF_PI 1.57079632679489661923f
```
NVG_MATH_TWO_PI [#nvg_math_two_pi]
```c title=" " lineNumbers=1
#define NVG_MATH_TWO_PI 6.28318530717958647692f
```
NVG_DEG_TO_RAD [#nvg_deg_to_rad]
```c title=" " lineNumbers=1
#define NVG_DEG_TO_RAD 0.017453292519943295769236907684886f
```
NVG_RAD_TO_DEG [#nvg_rad_to_deg]
```c title=" " lineNumbers=1
#define NVG_RAD_TO_DEG 57.295779513082320876798154814105f
```
NVG_MATH_TANF [#nvg_math_tanf]
```c title=" " lineNumbers=1
#define NVG_MATH_TANF(x) \
tanf(x)
```
NVG_MATH_SINF [#nvg_math_sinf]
```c title=" " lineNumbers=1
#define NVG_MATH_SINF(x) \
sinf(x)
```
NVG_MATH_COSF [#nvg_math_cosf]
```c title=" " lineNumbers=1
#define NVG_MATH_COSF(x) \
cosf(x)
```
NVG_MATH_ASINF [#nvg_math_asinf]
```c title=" " lineNumbers=1
#define NVG_MATH_ASINF(x) \
asinf(x)
```
NVG_MATH_ACOSF [#nvg_math_acosf]
```c title=" " lineNumbers=1
#define NVG_MATH_ACOSF(x) \
acosf(x)
```
NVG_MATH_FABSF [#nvg_math_fabsf]
```c title=" " lineNumbers=1
#define NVG_MATH_FABSF(x) \
fabsf(x)
```
NVG_MATH_SQRTF [#nvg_math_sqrtf]
```c title=" " lineNumbers=1
#define NVG_MATH_SQRTF(x) \
sqrtf(x)
```
NVG_MATH_RADIANS [#nvg_math_radians]
```c title=" " lineNumbers=1
#define NVG_MATH_RADIANS(deg) \
((deg) * NVG_DEG_TO_RAD)
```
NVG_MATH_DEGREES [#nvg_math_degrees]
```c title=" " lineNumbers=1
#define NVG_MATH_DEGREES(rad) \
((rad) * NVG_RAD_TO_DEG)
```
Dependencies [#dependencies]