## What is conjugate gradient in machine learning?

The conjugate gradient method is a line search method but for every move, it would not undo part of the moves done previously . It optimizes a quadratic equation in fewer step than the gradient ascent. If x is N-dimensional (N parameters), we can find the optimal point in at most N steps.

**Why do you need conjugate gradient method?**

In mathematics, the conjugate gradient method is an algorithm for the numerical solution of particular systems of linear equations, namely those whose matrix is positive-definite. The conjugate gradient method can also be used to solve unconstrained optimization problems such as energy minimization.

**What is the use of gradient in machine learning?**

In machine learning, a gradient is a derivative of a function that has more than one input variable. Known as the slope of a function in mathematical terms, the gradient simply measures the change in all weights with regard to the change in error.

### What is activation function Ann?

Simply put, an activation function is a function that is added into an artificial neural network in order to help the network learn complex patterns in the data. When comparing with a neuron-based model that is in our brains, the activation function is at the end deciding what is to be fired to the next neuron.

**What is the function of neural network in data mining?**

Neural networks are used for effective data mining in order to turn raw data into useful information. Neural networks look for patterns in large batches of data, allowing businesses to learn more about their customers which directs their marketing strategies, increase sales and lowers costs.

**What is the main drawback of conjugate direction method?**

The fundamental limitation of the conjugate gradient method is that it requires, in general, n cycles to reach the minimum. We need a procedure which will perform most of the function minimization in the first few cycles.

#### What are conjugate directions?

Two vectors, u, v, having this property are said to be conjugate. A set of vectors for which this holds for all pairs is a conjugate set. If we minimize along each of a conjugate set of n directions we will get closer to the minimum efficiently.

**What is optimization function in machine learning?**

Optimization is the problem of finding a set of inputs to an objective function that results in a maximum or minimum function evaluation. It is the challenging problem that underlies many machine learning algorithms, from fitting logistic regression models to training artificial neural networks.

**What is a gradient of a function?**

The gradient is a fancy word for derivative, or the rate of change of a function. It’s a vector (a direction to move) that. Points in the direction of greatest increase of a function (intuition on why) Is zero at a local maximum or local minimum (because there is no single direction of increase)

## What is the effect of learning rate in gradient descent algorithm?

Learning rate is used to scale the magnitude of parameter updates during gradient descent. The choice of the value for learning rate can impact two things: 1) how fast the algorithm learns and 2) whether the cost function is minimized or not.