precison -> precision

src/libm/k_rem_pio2.c

@@ -48,7 +48,7 @@
  *			64-bit  precision	2
  *			113-bit precision	3
  *		The actual value is the sum of them. Thus for 113-bit
- *		precison, one may have to do something like:
+ *		precision, one may have to do something like:
  *
  *		long double t,w,r_head, r_tail;
  *		t = (long double)y[2] + (long double)y[1];