A hyperplane in n dimensions is a n-1 dimensional subspace. For instance, a hyperplane in 1-dimensional space can be any line in that space and a hyperplane in 3-dimensional space can be any plane in that space. A hyperplane separates a space into two sides.

1. Representations - unanswered
2. Orthogonality check - unanswered
3. Perpendicular distance to plane - unanswered
4. Orthogonal projection onto plane - unanswered
5. Perpendicular distance to plane - unanswered
6. (f) - unanswered

I am here to help you with your questions about hyperplanes. Please let me know which specific topic you would like me to explain or which step you need assistance with.

I apologize for the incomplete response. Here are the answers to your questions:

1. Representations: In n-dimensional space, a hyperplane can be represented by an equation of the form a_1x_1 + a_2x_2 + ... + a_nx_n = b, where a_1, a_2, ..., a_n are constants and x_1, x_2, ..., x_n are the variables representing the coordinates in each dimension.

2. Orthogonality check: To check if a vector is orthogonal to a hyperplane, we can calculate the dot product of the vector with any vector that lies in the hyperplane. If the dot product is zero, then the vector is orthogonal to the hyperplane.

3. Perpendicular distance to plane: The perpendicular distance from a point to a hyperplane can be calculated as the absolute value of the signed distance between the point and the plane. This can be obtained by substituting the coordinates of the point into the equation of the hyperplane and taking the absolute value.

4. Orthogonal projection onto plane: The orthogonal projection of a point onto a hyperplane can be found by finding the point on the hyperplane that is closest to the given point. This can be done by finding the intersection between the line passing through the given point and perpendicular to the hyperplane.

6. (f) - I apologize, but I'm not sure what you mean by "(f)" in this context. Could you please provide more information or clarify your question?

If you have any further questions or need additional explanations, please let me know.