diff --git a/src/main/java/org/apache/commons/math/analysis/function/Sigmoid.java b/src/main/java/org/apache/commons/math/analysis/function/Sigmoid.java
index 5aa52e631..85d08a9b0 100644
--- a/src/main/java/org/apache/commons/math/analysis/function/Sigmoid.java
+++ b/src/main/java/org/apache/commons/math/analysis/function/Sigmoid.java
@@ -121,8 +121,6 @@ public class Sigmoid implements DifferentiableUnivariateRealFunction {
         public double[] gradient(double x, double ... param) {
             validateParameters(param);
 
-            final double lo = param[0];
-            final double hi = param[1];
             final double invExp1 = 1 / (1 + FastMath.exp(-x));
 
             return new double[] { 1 - invExp1, invExp1 };
diff --git a/src/test/java/org/apache/commons/math/optimization/MultiStartDifferentiableMultivariateRealOptimizerTest.java b/src/test/java/org/apache/commons/math/optimization/MultiStartDifferentiableMultivariateRealOptimizerTest.java
index ecd5f503e..2e3795347 100644
--- a/src/test/java/org/apache/commons/math/optimization/MultiStartDifferentiableMultivariateRealOptimizerTest.java
+++ b/src/test/java/org/apache/commons/math/optimization/MultiStartDifferentiableMultivariateRealOptimizerTest.java
@@ -24,7 +24,6 @@ import java.util.ArrayList;
 import org.apache.commons.math.analysis.DifferentiableMultivariateRealFunction;
 import org.apache.commons.math.analysis.MultivariateRealFunction;
 import org.apache.commons.math.analysis.MultivariateVectorialFunction;
-import org.apache.commons.math.analysis.solvers.BrentSolver;
 import org.apache.commons.math.optimization.general.ConjugateGradientFormula;
 import org.apache.commons.math.optimization.general.NonLinearConjugateGradientOptimizer;
 import org.apache.commons.math.random.GaussianRandomGenerator;
@@ -54,7 +53,6 @@ public class MultiStartDifferentiableMultivariateRealOptimizerTest {
         MultiStartDifferentiableMultivariateRealOptimizer optimizer =
             new MultiStartDifferentiableMultivariateRealOptimizer(underlying, 10, generator);
         optimizer.setConvergenceChecker(new SimpleScalarValueChecker(1.0e-10, 1.0e-10));
-        BrentSolver solver = new BrentSolver();
         RealPointValuePair optimum =
             optimizer.optimize(200, circle, GoalType.MINIMIZE, new double[] { 98.680, 47.345 });
         Assert.assertEquals(200, optimizer.getMaxEvaluations());
diff --git a/src/test/java/org/apache/commons/math/optimization/fitting/HarmonicFitterTest.java b/src/test/java/org/apache/commons/math/optimization/fitting/HarmonicFitterTest.java
index bf92b8db6..c08de3a6f 100644
--- a/src/test/java/org/apache/commons/math/optimization/fitting/HarmonicFitterTest.java
+++ b/src/test/java/org/apache/commons/math/optimization/fitting/HarmonicFitterTest.java
@@ -34,7 +34,7 @@ public class HarmonicFitterTest {
         HarmonicFitter fitter =
             new HarmonicFitter(new LevenbergMarquardtOptimizer());
 
-        final double[] fitted = fitter.fit();
+        fitter.fit();
     }
 
     // This test fails (throwing "ConvergenceException" instead).
@@ -108,7 +108,7 @@ public class HarmonicFitterTest {
             fitter.addObservedPoint(1, x, 1e-7 * randomizer.nextGaussian());
         }
 
-        final double[] fitted = fitter.fit();
+        fitter.fit();
         // This test serves to cover the part of the code of "guessAOmega"
         // when the algorithm using integrals fails.
     }