This result states first variation formula for area: given F: M m (N n,g) be a smooth immersion of a smooth m-manifold into a Riemannian manifold. Let > 0 and let F: (- , ) M N be a smooth map. For every t (- , ), define F t:M N by.... It is useful in minimal surfaces and harmonic maps, where variational identities, curvature estimates, and compactness arguments control geometric objects.