1 files changed, 3 insertions, 2 deletions
diff --git a/stokes.hpp b/stokes.hpp
index 60a3f55..b511b0d 100644
--- a/stokes.hpp
+++ b/stokes.hpp
@@ -28,11 +28,12 @@ public:
   }
 
   Real gCoeff(unsigned i, Real t) const {
-    return (1 - t) * t * pow(t, i);
+    return (1 - t) * t * std::legendre(i, 2 * t - 1);
   }
 
   Real dgCoeff(unsigned i, Real t) const {
-    return (i + 1) * (1 - t) * pow(t, i) - pow(t, i + 1);
+    Real x = 2 * t - 1;
+    return ((i - 1) * x * std::legendre(i, x) - (i + 1) * std::legendre(i + 1, x)) / 2.0;
   }
 
   Vector<Scalar> f(Real t) const {